To those who continue to bring here all kinds of "tactical nukes" BS just because they saw a "mushroom cloud".

1. Tactical nuke is defined as such NOT because of its yield, but because of its utility, that is--for solving tactical tasks. If the enemy's brigade spreads over large area and 2 to 5 kilotons are not enough, nobody prevents you from using 100kT device. It still will solve tactical level task only. Here is an example--Motorrifle Battalion attacking in one echelon with tactical nuke. 


Tactical being for achieving the tactical objective. It could be 2 kT, it could be something much more potent if, say, strong point is in the deep bunker. 

2. You cannot use nuke and not be immediately detected and identified by, say, Russia who has an advanced sensor network, including space-based Kupol which can see not only the flash (easily) and will know the nature of the charge, but it will know its yield but sensors will register all damaging factors of nuclear explosion ranging from flash to EMP, to radiation to a seismic event. The US knows this. Its use of nuke will be immediately detected and the user identified. What follows next--even majority nutjobs in D.C. can imagine. 

So, please, stop dragging here all kinds of hysterical X twits by some morons stating that because they saw "mushroom cloud" it is nuke.