Key difference:

1) In 2012 Hamas and othr Gaza terror groups like Jihadi Islami, PRC are FAR more powerful & better-equipped than in 2008. Iran has built impressive multi-billion dollar terror network in the midst of THE most densely populated area in the world. Since Mubarak's fall in Egypt, the border has been so porous that advanced Russian weapons have been smuggled in at a huge scale. In 2008, Castlead was a very difficult operation, but in 2012 it's a whole new level of Jihadi-clusterf*ck for Israelis. The world is also not going to tolerate 1,000+ Gaza deaths, which makes it even more difficult for IDF to fight guerilla warfare against an invisible enemy on his territory.

2) In 2008 Israel was led by a reactionary Left-wing clown Ehud Olmert who didn't know what he wanted to do from one minute to the next, as political winds kept on shifting. While Bibi is more talk than action, he is a tad more professional.

So of course the call-up has to be higher. Otherwise, IDF shouldn't even think about invading Gaza with what they had in 2008. No way, it wouldn't be worth it.