The U.S. has sent a message to Iran and North Korea by putting a request in the new emergency (for the war on terror) defense budget, an $88 million item for special B-2 bomber bomb racks to handle the new 15 ton bunker buster bomb (the MOP, or massive ordnance penetrator). There are no known targets for such a weapon in Iraq or Afghanistan, but there are plenty of such targets in Iran and North Korea. Moreover, even were there deep bunkers in Iraq or Afghanistan, you don't need a stealth bomber to deliver a MOP. The enemy in those countries have no way of detecting a high flying B-52, much less a stealthy B-2. But Iran and North Korea do have radars, and a B-2 could slip past those radars and take out the air defense system command bunkers, or any other targets buried deep. The 20 foot long MOP has a thick steel cap, and can penetrate up to 200 feet into the ground before exploding.