The White House came out in support of Israel on Thursday, with spokesman Jay Carney saying there is "no justification" for rocket fire from Gaza and urging militants to stop "cowardly acts."
However, the regional constellation has changed dramatically since the last Gaza war. Hamas has emerged from its political isolation as its parent movement, the region-wide Muslim Brotherhood, rose to power in several countries in the wake of last year's Arab Spring uprisings, particularly in Egypt.
On Thursday, the Egyptian president ordered his prime minister, Hesham Kandil, to lead a senior delegation to Gaza on Friday in a show of support for Hamas. Morsi has called Israel's campaign against Hamas "unacceptable" and has recalled Egypt's ambassador to Israel in protest.
Conflict at a glance
Militants in the Hamas-ruled Gaza Strip killed three Israeli civilians on Thursday in a rocket attack on a residential area.
The Israeli military has killed 19 Palestinians, both militants and civilians, in Gaza since the operation started Wednesday.
The Israeli military says it has hit more than 340 targets since the offensive began.
It also says Gaza militants fired around 450 rockets at Israel since the start of the operation. Three rockets targeted the densely populated Tel Aviv area.
Israel says its Iron Dome missile defense system has intercepted about 130 of those rockets.
- Film about man's crusade against child sex...
- Captain of sunken South Korean ferry, 2 crew...
- Creeping landslide devouring part of Jackson,...
- 13th body pulled from snow in Everest avalanche
- Some countries get Obama, but want his wife, too
- Get married, stay married? No fault divorce...
- Texas seizes FLDS Church's secluded ranch
- Ride-sharing business launches despite...
- Utah, Oklahoma same-sex marriage cases... 47
- The dangers of financially illiterate... 31
- Obama: 8 million signed up for health care 28
- Appeals judges question right to sue in... 27
- Texas seizes FLDS Church's secluded ranch 23
- Police: Student ate more pot than... 19
- Sentenced but never jailed, robber who... 16
- Supreme Court weighs ban on false... 15