Nuclear weapons as a fresh pillar of national security?

The crisis of American leadership, the variable attitude of U.S. president Donald Trump, as well as the papers that will shortly see the light of day and present the fresh approach of the United States to engagement in peculiar parts of the planet (National safety strategy and the paper "Global Posture Review" developed by the Vice-President of the Pentagon, Colby), make it possible for Washington's existing allies to ask whether the safety guarantees provided by Americans are inactive valid. This, in turn, makes it more and more common for those who, until recently, considered specified a script to be science-fiction.