It was an attack by the world's largest military machine. The truce was broken by Israel (as every truce has always been) because Israel was tired of waiting for an excuse to attack unarmed civilians. Hamas isn't allowed to be armed, or to have an air force or a navy, or tanks. This was no victory for Israel. Certainly Israel achieved its goal of killing Palestinians, but it has certainly lost in the forum of world opinion.
from the article: Senior Shin Bet official: Hamas completely lost Gaza war