It’s possible of course that (tin foil conspiracy hat donned for a moment) that Muslims, Commies and other enemies of the West are useful tools themselves. Any agenda that weakens us serves the overall purpose.
One thing I do believe is, if world leaders have been promoting the decline of the West in this manner, they have been very misguided and foolish. As you point out, Islam has irrational beliefs along with a desire to nuke Israel off the face of the earth. Nothing short of doing the same to adherents of that so-called religion will change that. It brings us right back to the doomsday scenario they supposedly want to avert.
My point was that the trouble with the Musslemen were evident 150 or so years before the invention of nuclear weapons.