( CNN ) -- The longstanding conflict between Israel and the Palestinian group Hamas reignited last week after Israel launched airstrikes against what it called terrorist targets in Gaza . Israel explained that the offensive , which it calls `` Operation Pillar of Defense , '' was necessitated by increasing rocket attacks from the Hamas-controlled territory . Are you there ? Share photos , video but stay safe . Among those killed in the Israeli airstrikes Wednesday was Ahmed al-Ja'abari , the chief of Hamas ' military wing . Weapons depots and rocket-launching sites were also targeted . `` Hamas and the other terrorist organizations in Gaza have made normal life impossible for over 1 million Israelis , '' Israeli Prime Minister Benjamin Netanyahu said in a statement . `` No government would tolerate a situation where nearly a fifth of its people live under a constant barrage of rockets and missile fire . '' Palestinian leaders condemned the attacks and said it is just another example of Israel 's aggression toward Gaza . Since Hamas took control of Gaza in 2007 , Israel has imposed a crippling economic embargo on the territory because it views Hamas as a terrorist organization bent on destroying the state of Israel . FAQ : What is Hamas , and what are its aims ? Meanwhile , Hamas ' military wing vowed revenge , warning that Israel had opened `` the gates of hell on themselves . '' Since then , Israel and Hamas have been trading bombs and rockets , and there is international concern that the situation could escalate into an even bloodier ground war . The Israeli government has called up 75,000 reservists and massed 30,000 troops across the border of the Palestinian territory , according to the Israel Defense Forces . `` If this situation continues and it escalates , it 's going to be really serious and tragic -- not just for Israelis and Palestinians , but actually it will cause a huge amount of upheaval right across the region , '' said former British Prime Minister Tony Blair , who is envoy for the Middle East Quartet working to find a peace agreement . `` And this is a region , as you know , that does n't require more upheaval right now . '' U.N. Secretary-General Ban Ki-moon flew to the region Monday to personally appeal for a cease-fire , joining a chorus of Western and Arab leaders who do not want to see a repeat of 2009 , when a three-week ground offensive resulted in the deaths of at least 1,400 Palestinians and 13 Israelis . But not all of those leaders view the conflict similarly . Many of the Western nations , including the United States and several European countries , see Hamas as the aggressor . U.S. President Barack Obama , speaking in Thailand on Sunday , said Hamas rocket attacks were the `` precipitating '' event for the fighting and that `` we are actively working with all the parties in the region to see if we can end those missiles being fired without further escalation of violence . '' The United States , like Israel , views Hamas as a terrorist organization . More : Obama 's telephone diplomacy on Gaza . Many Arab and Muslim nations , on the other hand , see Hamas as the victim of Israeli aggression . Egypt , for example , recalled its ambassador to Israel and delivered a formal protest to the Israeli government . `` No one can remain still and watch this tragedy unfold in this fashion , '' Egyptian Prime Minister Hesham Kandil said Friday . `` This is impossible . The whole world must intervene , and Israel must abide by the agreements and stop the aggression . '' Kandil visited a Gaza hospital and kissed the lifeless body of a 4-year-old boy said to have been killed by an Israeli airstrike . The Israeli military told CNN , however , that it did not carry out any strikes at the time of the child 's death ; it said it had stopped temporarily for Kandil 's visit . The death of civilians , especially children , has been a common rallying cry for critics of Israel 's offensive . Ten people , including several children , were pulled from the rubble after one airstrike in Gaza , as CNN 's Arwa Damon witnessed . Israeli authorities said they go to great lengths to avoid civilian casualties in densely populated Gaza , even dropping leaflets and nonlethal bombs to warn people about bombings in advance . But `` the terrorists , '' Netanyahu said , `` are committing a double war crime : They fire at Israeli civilians , and they hide behind Palestinian civilians . '' And sometimes , according to a tweet from the Israeli military , `` Hamas fires from civilian areas and hits its own people . '' Both Israel and Hamas have taken to Twitter to defend their cause and sway outside opinion . One recent graphic , tweeted from the account of Hamas ' military wing , said Israel is n't killing terrorists in Gaza ; it 's killing children , senior citizens and women . The Israeli military tweeted a graphic that asked , `` What would you do if rockets were striking your country ? RT if you agree that # Israel has the right to self-defense . '' As the fighting and the finger-pointing carry on , there 's no denying that suffering continues on both sides . CNN 's Sara Sidner interviewed one woman in Gaza who lost her two children , ages 2 and 4 . `` I am in shock , I ca n't believe it , '' Riba Abu Saithan said , crying . `` My two children , they are priceless to me . My life is now very difficult . '' In Ashkelon , a town in southern Israel , everyone is constantly afraid of rocket attacks , its mayor said . `` We ca n't go on like this , '' Mayor Benny Vaknin told CNN 's Frederik Pleitgen . `` We have 131,000 people here and 26,000 children . They are constantly under threat . '' Many experts expect that both Israel and Hamas will find it in their best interests to eventually stop fighting . Neither side has much to gain in repeating the events of 2009 , writes Aaron David Miller , a vice president and distinguished scholar at the Woodrow Wilson International Center for Scholars . Miller , who served as a Middle East negotiator in Democratic and Republican organizations , said : `` War did n't fix the problem then , and it 's unlikely to fix it now . Nor do the Israelis -- when the real threat is Iran -- want to get into a major military and political mess over Gaza that would make their relationship with Egypt even more complicated . '' More : Why Israel might hesitate to invade . But if war is n't the answer , why do the bombs and rockets continue to fly ? Nathan J . Brown , a professor of political science and international affairs at George Washington University , said each side suspects the other of playing domestic politics . `` Palestinians fear that the Israeli government is making war with an eye to upcoming elections . Israelis suspect that Hamas -- whose full name is the `` Islamic Resistance Movement '' -- is lobbing rockets because it is tired of its rivals ' taunting that it is not living up to its middle name , '' said Brown , who has authored six books on Middle East politics . There is some truth to these charges , Brown said , but both sides have other goals in mind . `` The Israelis know that they can not dislodge Hamas from Gaza without unacceptable cost and endless occupation . But they want to punish the movement so severely that it will be deterred from future violence , '' he said . `` Hamas knows that the damage it inflicts serves no strategic value , but it hopes that its rockets will cause dislocation and even panic in Israel and send an international message that Gaza can not be ignored . '' How Middle East has changed since last Gaza conflict . CNN 's Sara Sidner , Arwa Damon , Greg Botelho , Chelsea J. Carter , Kareem Khadder , Frederick Pleitgen , Mohammed Fadel Fahmy , Josh Levs , Saad Abedine , Talal Abu-Rahma , Hala Gorani , John D. Sutter and Bryony Jones contributed to this report .
Israel and Hamas have been trading bombs , rockets from afar . Israel said its military operation is in response to constant rocket attacks from Gaza . Palestinian leaders have condemned the attacks as a major escalation . Comment: