Analysts say continued tunneling at Natanz facility, revealed by recent satellite images, complicates calculations for US and Israel as nuclear deal remains stalled

Bunker-busting ordnance is kept at base home to B-2 stealth bombers, the only aircraft that can deploy the bomb; but depth of Natanz tunnels likely presents a serious challenge

Defense minister appears before Knesset committee, warns Iran nearly a 'threshold state,' after cabinet reportedly allocates NIS 5 billion for potential strike on nuke program

Sum said to include funds for aircraft, intel-gathering drones and unique armaments needed for attack; report comes days after US announces successful test of new bunker buster

Proposal would require DOD to consider transferring long-sought munitions capable of penetrating Iran's underground nuclear infrastructure, but move faces considerable hurdles