Guerilla warfare (like suicide bombs) is the strategy chosen by the weaker of two warring parties. "Hide, shoot & run" is the best strategy possible if you are facing a hugely overwhelming force. Basic 'Art of War' folks.

The stronger power always has the ability to frame the conflict. In this sense Israel/US is able to maintain the conflict in subtle ways ('low-intensity conflict').

Suicide bombs play well in the media, but you don't hear much about Israeli jets making regular sonic booms over populated Palastinian areas. People under constant stress have been known to freak out a bit, you know.