TORONTO (AP) — It began with Canada tweeting some not-so-friendly travel tips for the Russian military: a map showing Russia and labeling Ukraine as "not Russia." 
 
 This combination image shows a map tweeted by the Canadian Joint Delegation to NATO on Wednesday, Aug. 27, 2014, top, and a map tweeted in response on Thursday by the Twitter Feed of the Permanent Mission... (Associated Press) 
 
 That opening shot was enough to launch a Twitter war of words — and maps. 
 
 Canada's NATO Twitter account posted the map Wednesday with the explanation: "Geography can be tough. Here's a guide for Russian soldiers who keep getting lost and 'accidentally' enter Ukraine." 
 
 The tweet went viral, being retweeted more than 25,000 times by late Thursday, including by U.S. U.N. Ambassador Samantha Power. 
 
 Russia struck back by tweeting its own map showing Crimea as part of its territory. Russia annexed Crimea from Ukraine in March. 
 
 Kiev accused Russia on Thursday of sending tanks, artillery and troops across Ukraine's border. 
 
 Russia says its only active duty soldiers in Ukraine were the 10 captured earlier this week, who Moscow insists had mistakenly wandered across the border. 
 
 NATO estimates that as many as 1,000 Russian troops are fighting inside Ukraine with an additional 20,000 soldiers massing on the border for support or possible reinforcements. 
 
 "It's important to look at this exchange through the current context," said Rick Roth, the top spokesman for Canadian Foreign Affairs Minister John Baird. "The original tweet was in the context of Russian military personnel being found in sovereign Ukrainian territory, claiming they were lost. Nobody believes that." 
 
 Dutch Brig.-Gen. Nico Tak said there has been a significant escalation in both the level and sophistication of Russia's military interference in Ukraine. 
 
 "We have also detected large quantities of advanced weapons, including air defense systems, artillery, tanks, and armored personnel carriers being transferred to separatist forces in eastern Ukraine," said Tak. 
 
 Baird called the recent events a "significant provocation" in advance of next week's NATO summit in Wales, where the alliance's leaders are expected to hold a special meeting with new Ukrainian President Petro Poroshenko. 
 
 Ukraine is not a member of NATO, so the alliance is not automatically obliged to come to its defense. 
 
 President Barack Obama ruled out the possibility that the U.S. will take military action over Ukraine and declined to characterize the assault as an invasion. ||||| Image copyright Russian Nato Mission Image caption Russia posted this map in response to Canada's Twitter jab 
 
 This is Russia. This is "not Russia". 
 
 That's the message the Canadian Nato delegation tweeted, in map form, to Russian soldiers "who keep getting lost and 'accidentally' entering Ukraine". 
 
 "Geography can be tough," it notes snarkily. 
 
 On Tuesday Ukraine released video of Russian paratroopers it says it captured within its eastern border. In response, Russian military sources said the men had crossed an unmarked portion of the border "by accident". 
 
 Canadian officials, it seems, aren't buying the story. Since the tweet went live, Ukrainian President Petro Poroshenko has alleged that Russian troops have been "deployed" in eastern Ukraine 
 
 The map, which was sent out on Wednesday morning, has been retweeted more than 16,000 times. Users took to social media to offer their own commentary on geographically misguided Russians and Canadian "cheekiness". 
 
 Image copyright @ReeceEmmitt 
 
 "This is probably the most aggressive Canadian act since like 1812," tweets Kelsey D Atherton. 
 
 Of course, Americans could also probably use a little remedial geography instruction, if a poll conducted by the Washington Post in April is any indication. 
 
 Image copyright Stephen Saideman 
 
 Only 16% of respondents correctly located Ukraine on a map, and more than a hundred of the 2,066 participants seemed to think the Eastern European country was somewhere near Greenland or, ironically enough, Canada. 
 
 As the Toronto Globe and Mail reports, the tweet - which notably includes the contested Crimean region as part of "not Russia" - isn't an isolated instance of Canadian criticism of alleged Russian incursions into Ukraine. 
 
 Image copyright @CanadaNATO 
 
 "Russia's acts of aggression and intimidation toward Ukraine call for collective action," said Canadian Foreign Minister John Baird on Tuesday. "Canada, together with its like-minded allies, must clearly speak out." 
 
 An illustration did not accompany that statement. 
 
 UPDATE: A little more than 24 hours after the Canadian Nato delegation sent out its now-viral map, the Russian Nato delegation returned fire with a tweet from its official account. 
 
 "Helping our Canadian colleagues to catch up with contemporary geography of #Europe," was the message attached to a map of the area around the Black Sea. 
 
 Most notably, the Crimean Peninsula is labelled "Russia" and Abkhazia and South Ossetia - which have declared their independence from Georgia but have not been internationally recognised - are shaded. 
 
 Russia and Georgia fought a battle in 2008 over the territories, which still contain Russian forces. 
 
 Conveniently left unillustrated is the portion of Eastern Ukraine that is currently home to most of the fighting between Ukrainian forces and separatist rebels, where Ukraine says the Russian paratroopers were captured. 
 
 We anxiously await a Russian-produced map of Canada that shows an independent Quebec. It seems to be the way diplomacy is being conducted these days. 
 
 Reporting by Anthony Zurcher 
 
 You can follow BBC Trending on Twitter @BBCtrending 
 
 All our stories are at bbc.com/trending ||||| Image copyright Getty Images Image caption Knowledge of geography is not an American strength 
 
 A review of the best commentary on and around the world... 
 
 Today's must-read 
 
 A recent survey conducted by three US college professors found that only one in six Americans could find Ukraine on a map of the world. The results are plotted in one shame-inducing graphic. 
 
 What's more disturbing is that the farther away from the actual location of Ukraine the survey participants guessed, the more likely they were to support US military intervention. 
 
 A few of the 2,066 respondents seem to think Ukraine is somewhere in the central US, which certainly would make an armed response easier. Alaska - Alaska! - is the target of nearly a dozen guesses. 
 
 Greenland and northern Canada are peppered with dots. Brazil. South Africa. A spot in the ocean south of New Zealand. 
 
 Is it too much to hope that some of the people surveyed were just messing with the pollsters? 
 
 Political independents performed best, with 29% picking correctly. Republicans (15%) and Democrats (14%) were equally dismal. At least there's hope for the future. Twenty-seven per cent of Americans between 18 and 24 correctly located Ukraine. 
 
 Dartmouth Prof Kyle Dropp, Harvard Prof Joshua D Kertzer and Princeton Prof Thomas Zeitzoff write in the Washington Post that their survey reveals a disturbing truth: 
 
 Even controlling for a series of demographic characteristics and participants' general foreign policy attitudes, we found that the less accurate our participants were, the more they wanted the US to use force, the greater the threat they saw Russia as posing to US interests, and the more they thought that using force would advance US national security interests; all of these effects are statistically significant at a 95% confidence level. 
 
 It's worth noting, however, that no matter how woefully misinformed Americans are about Ukraine's actual location, only 13% of the total survey wanted to intervene militarily. 
 
 Canada 
 
 Time for a US-Canadian merger - Russia and China have their sights set on Canada's "rich and poorly defended open spaces", writes syndicated columnist Froma Harrop. If the US wants to protect its northern neighbour, she says, there's an obvious solution: a merger. 
 
 Harrop talks with the National Post's Diane Francis, who calls for a US-Canadian union in her new book, Merger of the Century. 
 
 "A merged Canada and US would occupy more land than Russia or all of South America," Harrop writes. "It would become an energy and economic powerhouse less subject to foreign intrigue. And few countries would mess with either of us." 
 
 Kenya 
 
 Terrorism and human rights - Kenya needs to have a "serious debate" about how to respond to the violence that has plagued the nation for three decades, writes Ken Nyaundi in the Standard. 
 
 While steps need to be taken to maintain security, he says, there is a price to be paid in liberty and the possibility that some steps taken could be counterproductive: "When we descend into a frenzied over-reaction, we drive terrorists further underground, generate sympathy for them and make them heroes". 
 
 Russia 
 
 Is a Ukraine invasion coming? - BBC's Jonathan Marcus analyses the latest information on Russian troop movements along the Ukrainian border and comes to the conclusion that the Russian military has learned from mistakes made in the 2008 invasion of Georgia. 
 
 Marcus talks with several experts who predict that Russia is capable of extended combat operations in Ukraine if it chooses to undertake them. 
 
 Ireland 
 
 British reconciliation - As Irish President Michael D Higgins makes the first-ever state visit to the UK on Tuesday, former President Mary Robinson remembers how differently she was treated on a non-official visit during her term in 1991. 
 
 "Because of Northern Ireland, the British would not agree to call me 'president of Ireland'!" she writes. 
 
 Her trip, she says, was a "carefully orchestrated meeting at head-of-state level between two countries with a troubled past seeking, in a symbolic way, to begin reconciling". 
 
 BBC Monitoring quote of the day 
 
 Iran and the powers have started the third round of nuclear talks. Representatives from Russia, the US, Britain, France, China and Germany - headed by EU foreign policy chief Catherine Ashton - are meeting Iranian Foreign Minister Mohammad Javad Zarif in Vienna. 
 
 One Iranian daily feels Tehran deserves praise for initiating the new rounds of talks: 
 
 "It seems that despite problems and suspicions created by domestic and American hard-liners, Iran's initiative to resume diplomatic negotiations was not considered as a sign of defeat and surrender, and Iran put an end to the propaganda created by Israel and some regional countries and secured its peaceful rights in the best way possible. As a result, Iran's nuclear industry remained intact and the country can perform its regional and international role with full respect." - Seyyed Ali Khorram in Iran's E'temad. 
 
 Have you found an interesting opinion piece about global issues that we missed? Share it with us via email at echochambers (at) bbc.co.uk. ||||| Image copyright Ukrainian Ministry of Defence Image caption Russian sources say the men were patrolling a section of the Russian-Ukrainian border 
 
 Ten Russian soldiers captured in eastern Ukraine crossed the border "by accident", Russian military sources are quoted as saying. 
 
 Ukraine has released video interviews of some of the seized paratroopers. 
 
 The incident comes as the Ukrainian and Russian leaders have held their first-ever bilateral talks in Belarus. 
 
 More than 2,000 people have died in months of fighting between Ukrainian forces and separatists in the Donetsk and Luhansk regions. 
 
 Media playback is unsupported on your device Media caption Steve Rosenberg says there's little optimism ahead of the talks in Belarus 
 
 The two regions declared independence from Kiev following Russia's annexation of the southern Crimean peninsula from Ukraine in March. 
 
 'Cannon fodder' 
 
 A Russian defence ministry source was quoted by the Russian news agency RIA Novosti as saying: "The soldiers really did participate in a patrol of a section of the Russian-Ukrainian border, crossed it by accident on an unmarked section, and as far as we understand showed no resistance to the armed forces of Ukraine when they were detained." 
 
 The source also said that some 500 Ukrainian servicemen had crossed the border at various times, adding: "We did not give much publicity to that. We just returned all those willing to return to Ukrainian territory at safe places." 
 
 Image copyright AP Image caption Smoke rises close to the town of Novoazovsk, where Ukrainian forces said they had engaged an armoured column from Russia 
 
 Ukraine's security service said its military had captured the 10 Russian paratroopers near the village of Dzerkalne, about 50km (30 miles) south-east of the rebel-held city of Donetsk and about 20km from the Russian border. 
 
 Ukrainian military spokesman Andriy Lysenko said: "This wasn't a mistake, but a special mission they were carrying out." 
 
 A Ukrainian television report that carried the interviews with the men said they were from the 331st regiment of the 98th Svirsk airborne division. 
 
 It quoted one man, named as Sgt Andrei Generalov, as saying: "Stop sending in our boys. Why? This is not our war. And if we weren't here, none of this would have happened." 
 
 Russia has repeatedly denied Ukrainian and Western accusations that it is supporting the rebels. 
 
 On Monday, Ukraine said an armoured column had crossed the border into south-eastern Ukraine, sparking clashes near Novoazovsk. 
 
 Mr Lysenko said on Tuesday that Ukrainian forces had destroyed 12 armoured infantry carriers there. He said 12 Ukrainian military personnel had been killed in the past 24 hours. 
 
 Mr Lysenko said four border guards had been killed by fire from Russian Mi-24 helicopters. 
 
 Border controls 
 
 Meanwhile, Ukrainian President Petro Poroshenko and his Russian counterpart, Vladimir Putin, have met behind closed doors to discuss the crisis at a summit in the Belarusian capital, Minsk. 
 
 So far no details have been released of their meeting. 
 
 Image copyright AFP Image caption Vladimir Putin (L) and Petro Poroshenko shook hands at the start of the summit 
 
 The summit is taking place under the auspices of the Moscow-led Eurasian Customs Union, which also includes Belarus and Kazakhstan. 
 
 It is also being attended by senior officials from the European Union which, along with the US, has imposed sanctions on Russia for failing to rein in the separatists. 
 
 Before they began their bilateral talks on Tuesday evening, Mr Putin said the current conflict could not "be resolved through further escalation of the use of force", and required direct dialogue with the separatists. 
 
 Mr Poroshenko has insisted that the only way to end the bloodshed and stabilise the region is by establishing effective border controls. 
 
 The pair last met briefly in June at the D-Day commemorations. 
 
 Analysis: The BBC's Oleg Boldyrev in Minsk 
 
 Image copyright AFP Image caption Belarusian honour guards at the summit in Minsk 
 
 The gulf between the positions of Ukraine and Russia is huge. Russia wants an unconditional ceasefire in eastern Ukraine. But Ukraine has the upper hand against the rebels there and does not want to simply stop and let them regroup. 
 
 Russia stresses that Ukraine must talk to the rebels, but Ukraine says the rebels are not a force of their own - rather an extension of Russia's hostilities, and it is Russia that must talk to the rebels and persuade them to lay down their weapons. 
 
 What will bridge this gulf after so many months of fighting remains unclear. ||||| Media playback is unsupported on your device Media caption Nato Secretary General Anders Fogh Rasmussen: "Russia is blatantly violating Ukrainian sovereignty" 
 
 Nato has accused Russia of a "blatant violation" of Ukraine's sovereignty and engaging in direct military operations to support pro-Russian rebels. 
 
 Secretary-General Anders Fogh Rasmussen said that "despite hollow denials", it was now clear that Russia had illegally crossed Ukraine's border. 
 
 He said Nato would respect any Ukrainian decision on security, after its PM said he was putting the country on course for Nato membership. 
 
 Russia denies sending troops and arms. 
 
 Russian President Vladimir Putin blamed the Ukrainian government for the crisis, comparing its siege of two cities held by separatists, Donetsk and Luhansk, to the siege of Leningrad by Nazi Germany in World War Two. 
 
 "It is necessary to make the Ukrainian authorities start substantial talks [with the rebels]," he said. 
 
 Media playback is unsupported on your device Media caption Putin: "The situation sadly reminds me of the Second World War" 
 
 Nearly 2,600 people have been killed since April, the UN says, when Russia's annexation of Crimea prompted the rebels to take control of large parts of Donetsk and Luhansk regions. 
 
 Heavy fighting is continuing near Ukraine's strategic port of Mariupol, on the Azov Sea. Rebel forces are trying to capture the city but Ukrainian government troops are digging in. 
 
 The rebel advance there has raised fears that the Kremlin might seek to create a land corridor between Russia and Crimea. 
 
 On Thursday the separatists seized the nearby town of Novoazovsk. 
 
 Separatists are also reported to have surrounded government soldiers in several places further north, near Donetsk city. 
 
 Ukrainian forces near the town of Ilovaysk say they are cut off and have been urgently asking for supplies and reinforcements. 
 
 Image copyright AFP Image caption Ukraine has long insisted Russian is sending troops and hardware to support eastern rebels 
 
 Image copyright AFP Image caption Residents of Mariupol are digging trenches to help Ukrainian soldiers defend the strategic port city 
 
 Image copyright AP Image caption An anti-war rally was held in Mariupol on Thursday 
 
 Image copyright Reuters Image caption Many buildings have been destroyed in heavy fighting in Donetsk region 
 
 Earlier, Ukrainian Prime Minister Arseny Yatsenyuk said the government was reopening the question of Nato membership. 
 
 He said it was sending a bill to parliament calling for Ukraine's non-aligned status to be cancelled, in effect paving the way for Ukraine to join Nato. 
 
 'Dangerous pattern' 
 
 Speaking at a news conference after an emergency meeting of Nato ambassadors, Mr Rasmussen said that it was clear Russia was engaged in direct military operations in Ukraine. 
 
 "This is not an isolated action, but part of a dangerous pattern over many months to destabilise Ukraine as a sovereign nation," he said. 
 
 "This is a blatant violation of Ukraine's sovereignty and territorial integrity. It defies all diplomatic efforts for a peaceful solution." 
 
 On Thursday, Nato had released satellite images it said showed columns of Russian armed forces inside Ukrainian territory, adding that more than 1,000 Russian troops were operating inside Ukraine. 
 
 Image copyright Reuters Image caption This satellite image provided by the Supreme Headquarters Allied Powers Europe shows what Nato identifies as Russian self-propelled artillery in Ukraine 
 
 Mr Rasmussen called on Russia to cease military action, stop supporting the rebels and "take immediate and verifiable steps towards de-escalation of this grave crisis". 
 
 Mr Rasmussen indicated Nato was open to considering Ukraine's application to join if it met the conditions. 
 
 In 2008, Ukraine applied for Nato membership under then-President Viktor Yushchenko. 
 
 But the plans were shelved two years later when Viktor Yanukovych came to power and ended Ukraine's Nato ambitions in favour of mending relations with Russia. 
 
 Mr Rasmussen said on Friday: "I am not going to interfere with political discussions in Ukraine, but let me remind you of Nato's decision taken at the Bucharest Summit in 2008 according to which Ukraine will become a member of Nato, provided of course that Ukraine so wishes and provided that Ukraine fulfils the necessary criteria." 
 
 Analysis: Paul Adams, BBC News 
 
 Ukraine's prospects for Nato membership seem dim. 
 
 The 2008 pledge, made at the insistence of then-US President George W Bush, was criticised at the time. Some saw it as rash and needlessly provocative towards Moscow, which has long argued that the West broke a promise not to extend the alliance into the former Soviet bloc after the end of the Cold War. 
 
 Georgia's brief war with Russia, in the summer of 2008, convinced sceptics that for Nato to embrace countries with unresolved territorial disputes with Russia was not worth the risk. 
 
 And while the Ukrainian government wants it, what evidence is there that enough Ukrainians share the same enthusiasm? Opinion polls in 2008 suggested only about 30% of the population favoured membership. In the midst of Ukraine's worsening civil war, opinion is unlikely to be less divided. 
 
 Image copyright AFP Image caption A new UN report says civilians are being deliberated targeted in the fighting 
 
 A UN report released on Friday found that serious human rights abuses had been committed by rebels and Ukrainian forces. 
 
 The abuses include the deliberate targeting and killing of civilians trapped in urban areas or trying to flee the fighting via government-established "safe corridors", the study found. 
 
 It said that an average of around 36 people had been killed on a daily basis between 16 July and 17 August. 
 
 War in eastern Ukraine: The human cost 
 
 At least 2,593 people had been killed since mid-April, not including the 298 passengers and crew of the Malaysian Airlines MH17 shot down in the area, a UN report on 7 August said 
 
 951 civilians have been killed in Donetsk region alone, the official regional authorities said on 20 August 
 
 Official casualty counts only record certified deaths while in some particularly dangerous parts of the war zone, such as Luhansk region, victims are said to have been buried informally, for instance in gardens 
 
 Rebels (and some military sources) accuse the government of concealing the true numbers of soldiers killed 
 
 155,800 people have fled elsewhere in Ukraine while at least 188,000 have gone to Russia. 
 
 Have you been affected by what's going on in Ukraine? Tell us your story by emailing us at haveyoursay@bbc.co.uk
– Canadian officials had a message for Vladimir Putin this week: Here's where Russia isn't. NATO delegates from Canada tweeted a simplified map Wednesday that delineates Russia's borders, calling Russia "Russia" and Ukraine (including the Crimean region) "not Russia," the AP reports. "Geography can be tough," reads the message, which has been retweeted more than 36,000 times as of this writing. "Here's a guide for Russian soldiers who keep getting lost and 'accidentally' enter Ukraine." Russia still insists it isn't invading Ukraine, and says the only Russian soldiers to cross over were 10 guys who did so by mistake earlier this week. In fact, Russia's NATO delegation tweeted its own map showing the Crimean peninsula as belonging to Russia: "Helping our Canadian colleagues to catch up with contemporary geography of #Europe," it reads. Yet Russia's map "conveniently left unillustrated" the part of eastern Ukraine where the 10 Russian soldiers were said to be captured, the BBC notes. So, all of this was sparked by friendly old Canada? "This is probably the most aggressive Canadian act since like 1812," cracked one tweeter. But some Americans need help even finding Ukraine, according to one study: Only 16% could spot it on a map, and over 100 of the 2,066 participants figured it was near Greenland—or, appropriately, Canada, the BBC reports. (A Bulgarian artist created maps that depict typical American stereotypes of countries across the pond.)