The new US policy is a very dangerous one. By making this statement in public Obama has given the green light for his generals to consider the use of tactical nuclear weapons against conventional forces. The first trial use will likely be the from the use of 'bunker buster' and area denial weapons against dug in / cave dwelling 'terrorists' in certain areas of Afghanistan, maybe even right up to the border with Pakistan. If the world does not kick up much fuss we may then even see a first strike against Iranian infrastucture made with small tactical nuclear weapons carried by ship launched cruise missiles or even the latest supossidly secret fast jet type drones. Such an attack would devestate Irans ability to counter strike in any meaningful way, or even defend themselves against subsequent carrier launched air attacks or ground incursions from Iraq and Afghanistan. Advantages to a first strike using small nuclear warheads delivered by unmaned methods such as drones or missiles would include very little risk to US service personnel, low financial outlay - at least not particularly expensive when compared with other options - and maxium devestation over a very short time span. Almost everything required is even in place now. Iran is well prepared for a convential assault, but could not survive a nuclear attack, even by 'small' tactical weapons that did not target its population centres, only civil and military infrastructure. Maybe this is the ultimate sanction that will threaten Iran if it does not capitulate and except the US, if not as its master, then as the undisputed master of the region.