This is the fictional country the Russians are training to fight

Russia is sending what NATO thinks is thousands of troops into Belarus – and the transatlantic alliance is worried the Russians may not leave. The move would pose a counter to the recent movement of NATO forces into the area, including former Soviet states Latvia, Lithuania, Estonia, Romania, and Poland.

Every four years, the Russian military conducts its Zapad military exercise with neighboring Belarus. In the exercise, three "aggressor countries" (Veishnoriya, Vesbaria, and Lubenia) attack Belarus. Veishnoriya, according to legend, is located in the western part of Belarus; Vesbaria is on the territory of Lithuania and Latvia; Lubenia in Lithuania and Poland. The two intervening countries are pro-Western client states.

The Russian and Belorussian response, they claim, is purely defensive. The Russians say it emulates a terrorist threat with external support – that support comes from the West, which the Russian military will move to counter.

Just as Americans embrace the fictional countries the U.S. military uses to train its troops, fictional Twitter and Facebook accounts representing Veishnoriya's various official ministries have popped up around the war games. There are even fictional seals, flags, and histories surrounding the fictional country. You can even apply for a Veishnoriyan passport.

One Facebook discussion boasted that Veishnoriya has never lost a war, while detractors say, "It's not Vesbaria, it's not Lubenia. Volodya, your soldiers will be torn to pieces!"

An estimated three thousand to 100,000 Russian troops are involved (depending on who you ask), along with the Russian 1st Guard Tank Army. It's an exercise they've been running every four years since the 1970s, except for the decade or so after the fall of the Soviet Union.

NATO experts believe the game represents what Moscow thinks is a scenario most likely to come from Western efforts to undermine the Russian sphere of influence.

If the war game did have upwards of 100,000 troops and tanks, the Russians would be required to report the exercise and submit to having foreign observers monitor the exercise, according to the Vienna Document, a 2011 security agreement.

The Russians say it involves just 12,700 troops, 300 shy of the number that would trigger the Vienna agreement. But even if the West isn't able to observe the exercise, they can still monitor Russian troop movements, something experts say will give NATO a good idea of just how capable the Russian military can be.