The French Triomphant-class sub is very distinctive. Three masts, one with a bulb at the end. The tail planes are submerged. The crew are dressed in orange coveralls. It has smooth lines. It carries 16 M51 ballistic missiles with 6-10 warheads.

There are four in the class, all based at Île Longue near Brest, France.

https://en.wikipedia.org/wiki/Triomphant-class_submarine

Rationale for launch: After the Bilderberg Group meets to coordinate, the globalists confront President Trump at the G7. He does not budge. The missile launch hits North Korea. The US gets blamed (Trump had made threats and the missile was launched near a US ballistic missile submarine base. China & US have a nuclear war. The US and China are devastated. The global population is reduced by 1 billion. NATO disavows the US, since it started the war. The EU is untouched and fills the vacuum to become the world’s lone superpower.