In short, and very simply - it means the nuke is smaller and more focused.<p>From my time in combat zones - we always thought of tactical as the level at which a battalion or lower might operate.  Strategic would be entire regiments or larger, potentially involving entire countries.<p>A nuke that clears the path for a battalion (political implications of using a nuclear weapon aside) is tactical.  A nuke that eliminates a capital or engulfs many battalions in flames is strategic.<p>I would imagine, though, that a &quot;tactical-sized&quot;, or smaller, nuke could have strategic implications if you detonated it somewhere of great import (eliminating the leadership while all in one building, for example).  This would be a strategic use of a nuke.<p>But in actuality - it is very complicated.  Something like a nuclear weapon is a multifaceted action and cannot be distilled to a single word.