"We have no idea how this could have happened."

That is the reaction Israeli officials have been giving today when I ask them how, with all its vast resources, Israeli intelligence did not see this attack coming.

Dozens of armed Palestinian gunmen were able to cross the heavily fortified border between Israel and the Gaza Strip, while thousands of rockets were fired from Gaza into Israel.

With the combined efforts of Shin Bet, Israeli domestic intelligence, Mossad, its external spy agency and all the assets of the Israel Defense Forces, it is frankly astounding that nobody saw this coming.

Or if they did, they failed to act on it.