Well, at a certain point it changes the geopolitical calculus. Not that nuclear war should ever be entered into lightly. But guaranteed human extinction pretty

Well, at a certain point it changes the geopolitical calculus. Not that nuclear war should ever be entered into lightly. But guaranteed human extinction pretty much rules out any and all justification. In the most anti-nuclear paradigms, even second-strike is off the table, because it only exacerbates nuclear winter. Whereas if nuclear war is winnable, as Pentagon strategists have been saying since the 1950s, then first nuclear strike should probably still be on the table for certain extreme geopolitical situations. So, the question seems pretty relevant in that it's a major determinant in terms of setting optimal military doctrine.