The only reason the Communists managed to succeed Russia is due to the interim government staying in the war after the Czar was deposed.
Something that only happened thanks to US loans to Russia in exchange for Russia staying in the war. This angered the Russian people, who the Soviets then played off of and allowed them to gain popular support.
Never mind that without US loans the entente would never have been able to afford the war after 1916 abouts. Or how US troops massively raised French and British moral and kept the French mutinies from exploding.
Oh so you'd prevent all trade and financial investment in the rest of the world in 1914, not just military isolation?
And this is something you'd want to maintain consistently with any belligerent of conflicts in perpetuity more or less?