“What would stop it?”
What HAS stopped it to date is the fear that foreign governments have of mutually assured destruction.
For example:
The United States Navy has 14 nuclear submarines currently armed with Trident II missiles. The 14 Trident II ballistic missile submarines carry approximately fifty percent of the total U.S. active inventory of strategic thermonuclear warheads.
Nero,
For once I agree with you.
That “tip of the spear” is a formidable deterrent indeed!!!!!!!
G-d help any nation (or rogue group) crossing that front line defense!!!!!