Coutryhumans / War's Vessel / Alternate universe

[WARNING! may be offensive, this isn't made to offend anyone. if you don't like the book, please don't read it, thank you for understanding]
after a mysterious nuke landed in Moscow, countries keep on arguing until wold war 3 happened and destroyed everything, including everyone's trust.
Who launched the Nuke? What happened during the war?

This book is a combination of Detective (the start of the book) and war

this story was a collab with @PurpleSofty123, but she only helped on chapter 1 and isn't helping me write the story anymore since she isn't really focusing on WattPad anymore