During the 1982 Falklands War, in a meeting of Haringey Council, Corbyn opposed a motion offering support to British troops sent to retake the islands, instead declaring the war to be a "Tory plot" and submitted an alternative motion that condemned the war as a "nauseating waste of lives and money".
Corbyn has said that he would like Britain to achieve "some reasonable accommodation" with Argentina over their Falkland Islands dispute, with a "degree of joint administration" between the two countries over the islands.

Corbyn does not consider himself an absolute pacifist and has named the Spanish Civil War, the British naval blockade to stop the slave trade in the 19th century and the role of UN peacekeepers in the 1999 crisis in East Timor as justified conflicts.
Opposing violence and war has been "the whole purpose of his life".
He prominently opposed the invasion of Iraq and War in Afghanistan, NATO-led military intervention in Libya, military strikes against Assad's Syria, and military action against ISIS, and served as the chair of the Stop the War Coalition.
When challenged on whether there were any circumstances in which he would deploy military forces overseas he said "I'm sure there are some but I can't think of them at the moment."

Corbyn has called for Tony Blair to be investigated for alleged war crimes during the Iraq War.

In July 2016, the Chilcot report of the Iraq Inquiry was issued, criticising the former Labour PM Tony Blair for joining the United States in the war against Iraq.
Subsequently, Corbyn  – who had voted against military action against Iraq – gave a speech in Westminster commenting: "I now apologise sincerely on behalf of my party for the disastrous decision to go to war in Iraq in March 2003" which he called an "act of military aggression launched on a false pretext" something that has "long been regarded as illegal by the overwhelming weight of international opinion".
Corbyn specifically apologised to "the people of Iraq"; to the families of British soldiers who died in Iraq or returned injured; and to "the millions of British citizens who feel our democracy was traduced and undermined by the way in which the decision to go to war was taken on."

Corbyn has said he would prefer to use diplomacy rather than armed force in international conflict.
He would avoid military conflict by "building up the diplomatic relationships and also trying to not isolate any country in Europe".
His aim is to "achieve a world where we don't need to go to war, where there is no need for it".

NATO and nuclear weapons
Corbyn favours the United Kingdom leaving NATO.
In May 2012, Corbyn authored a piece in the Morning Star titled "High time for an end to NATO" where he described the organisation as an "instrument of cold war manipulation", saying that "The collapse of the Soviet Union in 1990, with the ending of the Warsaw Pact mutual defence strategy, was the obvious time for NATO to have been disbanded."
and also said a 2014 speech that the organisation was an "engine for the delivery of oil to the oil companies" and called for it to "give up, go home and go away".

For these comments and a refusal to answer whether he would defend a NATO ally in the case of attack he was criticised by Anders Fogh Rasmussen, the former Prime Minister of Denmark and NATO Secretary General, who said Corbyn's opinions were "tempting President Putin to aggression" and made comparisons between his views and those of the American president Donald Trump.
He was also criticised by George Robertson, former Labour Party defence secretary, who said "It beggars belief that the leader of the party most responsible for the collective security pact of NATO should be so reckless as to undermine it by refusing to say he would come to the aid of an ally".

He has since acknowledged that the British public do not agree with his beliefs that the UK should leave NATO, and instead intends to push for the organisation to "restrict its role".
He believes there should be a debate about the extent of NATO's powers including its "democratic accountability" and
During the 1982 Falklands War, in a meeting of Haringey Council, Corbyn opposed a motion offering support to British troops sent to retake the islands, instead declaring the war to be a "Tory plot" and submitted an alternative motion that condemned the war as a "nauseating waste of lives and money". Corbyn has said that he would like Britain to achieve "some reasonable accommodation" with Argentina over their Falkland Islands dispute, with a "degree of joint administration" between the two countries over the islands.
Corbyn does not consider himself an absolute pacifist and has named the Spanish Civil War, the British naval blockade to stop the slave trade in the 19th century and the role of UN peacekeepers in the 1999 crisis in East Timor as justified conflicts. Opposing violence and war has been "the whole purpose of his life". He prominently opposed the invasion of Iraq and War in Afghanistan, NATO-led military intervention in Libya, military strikes against Assad's Syria, and military action against ISIS, and served as the chair of the Stop the War Coalition. When challenged on whether there were any circumstances in which he would deploy military forces overseas he said "I'm sure there are some but I can't think of them at the moment."
Corbyn has called for Tony Blair to be investigated for alleged war crimes during the Iraq War.
In July 2016, the Chilcot report of the Iraq Inquiry was issued, criticising the former Labour PM Tony Blair for joining the United States in the war against Iraq. Subsequently, Corbyn  – who had voted against military action against Iraq – gave a speech in Westminster commenting: "I now apologise sincerely on behalf of my party for the disastrous decision to go to war in Iraq in March 2003" which he called an "act of military aggression launched on a false pretext" something that has "long been regarded as illegal by the overwhelming weight of international opinion". Corbyn specifically apologised to "the people of Iraq"; to the families of British soldiers who died in Iraq or returned injured; and to "the millions of British citizens who feel our democracy was traduced and undermined by the way in which the decision to go to war was taken on."
Corbyn has said he would prefer to use diplomacy rather than armed force in international conflict. He would avoid military conflict by "building up the diplomatic relationships and also trying to not isolate any country in Europe". His aim is to "achieve a world where we don't need to go to war, where there is no need for it".
NATO and nuclear weapons
Corbyn favours the United Kingdom leaving NATO. In May 2012, Corbyn authored a piece in the Morning Star titled "High time for an end to NATO" where he described the organisation as an "instrument of cold war manipulation", saying that "The collapse of the Soviet Union in 1990, with the ending of the Warsaw Pact mutual defence strategy, was the obvious time for NATO to have been disbanded." and also said a 2014 speech that the organisation was an "engine for the delivery of oil to the oil companies" and called for it to "give up, go home and go away".
For these comments and a refusal to answer whether he would defend a NATO ally in the case of attack he was criticised by Anders Fogh Rasmussen, the former Prime Minister of Denmark and NATO Secretary General, who said Corbyn's opinions were "tempting President Putin to aggression" and made comparisons between his views and those of the American president Donald Trump. He was also criticised by George Robertson, former Labour Party defence secretary, who said "It beggars belief that the leader of the party most responsible for the collective security pact of NATO should be so reckless as to undermine it by refusing to say he would come to the aid of an ally".
He has since acknowledged that the British public do not agree with his beliefs that the UK should leave NATO, and instead intends to push for the organisation to "restrict its role". He believes there should be a debate about the extent of NATO's powers including its "democratic accountability" and
Jeremy Corbyn