For centuries, many civilizations have tried (for one reason or another) to subdue or kill the Russian Bear.

Most of them failed.

To successfully plant their flag atop the Kremlin, an invader must consider a few things that’ll certainly affect the outcome before mobilizing forces and gassing up the fleet.

1. The Russian Winter

Pro Tip: Pack your woobie.

In 2014, Vice’s Oscar Rickett asked IHS Jane’s military expert Konrad Muzkya just what it would take to conquer Russia and just how a nation might go about it. His first question is one that sticks in the minds of any student of military history: How does anyone beat the Russian winter?

In case you thought you could handle winter like a Russian, this is how they celebrate Epiphany in the Russian Orthodox Church.With Napoleon and Hitler waiting with bated breath in the next world, Muzkya replies with his belief that guided munitions, nuclear weapons, and modern power projection capabilities nullify this historical advantage.

“Any potential conflict with the West would most likely be fought in the air, space, and sea,” he told Vice. “Any use of land forces would be limited to capturing strategically important facilities — bridges, airfields, and the like.”

2. The Size of Russia

To give the failed invaders a little credit, the Russia conquered by the Mongols was a fraction of the size it was during the 19th and 20th centuries. But a little secret to the Mongols success might have been preparation. The Khans took 17 years to finish off the Russians.

It wasn’t a lack of manpower, either. At the time of the French Invasion, Napoleon’s Grande Armée numbered 680,000 troops.

To give some perspective, that’s like deploying half of all the active U.S. military troops as riflemen. Which is a terrible idea.

Trying to conquer Russia is the equivalent of invading the U.S. twice, in terms of landmass. Just moving from St. Petersburg to Moscow is 400 miles. It took the Allies more than two months to reach Paris from the Normandy — which is just 167 miles away.

Russia is 6.6 million square miles of cold, cold, cold, nothing. Which presents another problem entirely.

3. There’s Nothing There

Everything after Moscow is flyover country. An invading country can’t just not go into the steppe. Once the Russian people figured out the occupiers won’t go into the wilderness, you can expect that this is where exactly an insurgency would take root.

Even getting to all the nothing will take a Herculean effort. The Russian Army mans an estimated 280,000 effective fighting soldiers. When the going gets tough, it has to be assumed they will use the same human wave-style tactics used against the Nazis in WWII.

What was a problem in the past for armies who had to forage for food or move supplies by train is not a problem for a global power like the U.S. military. All the same, after Moscow, there isn’t much in the way of infrastructure for things like tanks or places suitable for airfields — all things insurgent partisans in the area will have a field day targeting.

4. One Thing at a Time

Anyone who wants to invade Russia should probably clear their schedule. The Mongols drove through the country because it was on the way to where they were going anyway. The Nazis were still fighting in North Africa and preparing for the invasion of Britain when Hitler launched Barbarossa. Napoleon was fighting an insurgency of his own in Spain.

The United States and NATO, if they were to invade Russia, should probably withdraw from all the other conflicts they have around the world and concentrate on the problem at hand. Once there, keeping a unified front would be of the utmost importance.

An invader shouldn’t expect to actually conquer anything. In almost every invasion of their motherland, the Russian people have resorted to scorched-earth tactics — burning or otherwise destroying everything that might be of use to an enemy. As Muzkya notes in the Vice article, the Russians still move troops using trains. That hasn’t changed since WWII. It’s likely not much else has either.

5. Bring Some Friends… and an Air Force

Muzkya cites an estimate of a half-million troops being necessary to properly subdue Afghanistan. He also notes that Russia is 26 times the size of Afghanistan and has a population of 143 million. Afghanistan has just 30 million. Even the Chinese military with its massive available manpower would have a difficult time creating a sustainable drive across Russia.

But a military campaign is more than just people these days. The Russian Navy can’t project power in the same way the U.S. can – or anyone else, really. The country has only one aircraft carrier, and that deploys with a tugboat in case it breaks down.

The Russian air force, however, is still on the relative cutting edge, even if that edge isn’t as sharp as it once was. It has a fighter that can compete with the Air Force’s F-22 Raptor. Russia’s bomber force isn’t relevant in a defensive war because it’s more likely they’d use a nuclear attack before a conventional bombing campaign on their own soil.

6. Be Prepared to Die

As for the use of nuclear weapons, Muzkya says that Russia has the right to use them to defend itself and any invader needs to be prepared for that.

“Russia possesses second-strike capability,” he says. “And unless you’re ready to take a nuclear hit from Russia — which no one can — you need to embrace the notion of a total annihilation of your country.”

He predicts that Russia – all 6.6 million square miles of it – would be turned into a nuclear wasteland in the event of an invasion from China or the West, so talking about who wins is irrelevant.

Because everyone dies.