Israel says it killed 1,500 Hamas terrorists, pointing to a brutal fight ahead in Gaza

Among the grim, extraordinary numbers that tell the story of the militants' attack on Israel, that one, in particular, has dumbfounded experts. It raises the question of how large Hamas' total fighting force is — and what a bloody, close-quarters ground offensive on the Gaza Strip might look like if Israel launches one in the coming days. “I don’t think there’s a way to overstate how extraordinarily difficult it will be,” Tobias Borck, a Middle East expert at the Royal United Services Institute, a London think tank, told NBC News. “It’s not going to just be street-by-street, but house-by-house and tunnel-by-tunnel."