How did Lenin and the the Bolshevik leaders get back in after they were exiled from Russia?

Germany smuggled the Bolshevik leaders back in, figuring it was the easiest way of getting Russia out of World War I.

Even though Czar Nicholas had abdicated, the provisional government that took over continued fighting in World War I.

Sowing seeds of trouble that they’d have reason to regret for decades afterward, the Germans decided that throwing the Bolsheviks back into the mix would be a good way to keep Russia destabilized.

The Germans commissioned a special train to take Lenin and thirty-two other Bolsheviks to Petrograd hoping they would act, as Winston Churchill put it later, “like a typhoid bacillus.” The tactic worked.

When the Bolsheviks seized power, they signed a peace treaty with Germany in which Russia granted huge concessions.

However, the last laugh was on them, Germany continued to drive forward into their territories despite the treaty, capturing huge chunks of land, and the Russian army was too weak from the revolution to resist.