The Israeli operation started with an intense bombardment of the Gaza Strip, carried out by the Israeli Air Force and navy^{[43][44][45][46][47][48][49][50][51]} targeting Hamas bases, training camps, headquarters and offices.^[52][53] Civilian infrastructure, including mosques, houses and schools, were also attacked. Israel said many of these buildings stocked weapons.^{[54][55][56][57][58][59][60]} Hamas intensified its rocket and mortar attacks against targets in Israel throughout the conflict, hitting such cities as Beersheba and Ashdod.^{[61][62][63][64][65]} On January 3, 2009, the Israeli Defence Forces ground invasion began, with mechanised infantry, armor, and artillery units, supported by helicopter gunships, entering Gaza.^[66][67]

As of 6 February, 2009, 14 Israelis have been killed during this conflict, including three civilians. According to figures compiled by the Palestinian Ministry of Health, about 1,300+ Palestinians were killed including 900+ civilians of whom 410 were children (with the remainder being police officers and militants).^[68][69] The Israeli military claims that between 1,100 and 1,200 Palestinians comprising 700 militants and 250 civilians were killed.^{[70][71][72][73][74]} In the days following the ceasefire, the BBC reported that more than 400,000 Gazans were left without running water.^[75] As a result of the bombings, 4,000 Gazan buildings were razed ^[75] and 20,000 severely damaged.^[75]

International reactions during the conflict have included calls for an immediate ceasefire as in the United Nations Security Council Resolution 1860, and concern about the humanitarian situation in the Gaza Strip and the hindrances in delivering aid.^{[76][77][78][79]} Israel announced a unilateral ceasefire on January 18 which came in effect at 0000 UTC (2 a.m. local time). Hamas offered its own one-week unilateral ceasefire.^[80][81] On 21 January, Israel completed its withdrawal from the Gaza Strip.^[82]

Human rights groups and aid organisations have accused Hamas and Israel of war crimes and called for independent investigations and lawsuits.

The Gaza Strip is one of the most densely populated places on earth.^[89] According to the CIA Factbook as of July 2008, it holds a population of 1,500,202. on an area of 360 square kilometers (139 sq mi).

Hamas assumed administrative control of Gaza following the 2006 Palestinian legislative elections and its 2007 military victory over Fatah. Subsequently, Egypt closed the Rafah Border Crossing when EU monitors left and Israel closed off all remaining access to Gaza in July 2007. ^[90] The blockade allowed Israel to control the flow of goods going into Gaza, including power and water. Israel halted all exports and only allowed shipments into Gaza to avert a humanitarian crisis.^[91] Palestinian groups were partially able to bypass the blockade through tunnels, which Israel alleges were used for weapons smuggling.^[92] Between 2005 and the start of the 2008/2009 conflict, Palestinian groups launched over 8,000 rocket and missile attacks into Israel, killing twelve people and wounding dozens more.^[93] During this time period Israeli air strikes, targeted killings, and undercover operations have killed more than 800 Palestinians.^[94]

Hamas views Israel as an illegitimate state and its charter calls for the destruction of Israel.^[95] Meanwhile, Ismail Haniyeh, the political leader of Hamas, stated that the Hamas government had agreed to accept a Palestinian state that followed the 1967 border and to offer Israel a long-term truce, if Israel recognized the Palestinians' national rights.^[96] Israel views Hamas as a terrorist group that must be dismantled