Where 100,000 U.S. troops are stationed in Europe

President Biden will meet Friday with U.S. troops stationed in Poland, a key NATO ally currently housing 10,500 of the 100,000 American service members now deployed across Europe.

Why it matters: Russia invaded Ukraine with a force estimated at 190,000. The last time the U.S. had 100,000 troops deployed in Europe was 2005, during the early years of the Global War on Terror, according to a history of U.S. force posture provided by U.S. European Command.

• NATO Secretary-General Jens Stoltenberg said last week the alliance must "reset" as a result of the "new security reality" created by Russia's invasion and its military integration with Belarus.
• What that reset looks like will be a top priority when Biden attends an emergency NATO summit in Brussels on Thursday.

By the numbers: After an initial post-World War II demobilization, the number of U.S. troops in Europe surged from 97,000 in 1950 to over 450,000 in 1957.

• That was the first of two major Cold War buildups, with the second peaking at about 340,000 troops in 1987.
• In 2018, the number of U.S. troops in Europe bottomed out at around 65,000, the posture history shows.

The big picture: Since Russia's military buildup on Ukraine's border began in October, the U.S. and other NATO countries have deployed thousands of troops to reinforce eastern-flank countries like Poland, Lithuania, Latvia, Estonia, Bulgaria and Romania.

• Hundreds of thousands of NATO forces, comprised of troops under both national and NATO command, are on heightened alert across the alliance.
• They're backed by significant air and naval power, including 130 allied aircraft on high alert and 140 allied ships at sea, as well as sophisticated air defense systems.

Worth noting: The U.S. also has troops stationed in 10 non-NATO countries for peacekeeping and other cooperation missions.

• They include Kosovo (800), Cyprus (100) and the potential future NATO members of Sweden (10) and Finland (5).

What to watch: Biden will use his Europe trip to work with allies on "longer-term adjustments to NATO force posture on the eastern flank," national security adviser Jake Sullivan said Tuesday.

• That could potentially include a more permanent troop deployment in the Baltic states, which have been calling for reinforcement and sounding the alarm about Russian aggression for years.
• NATO had previously resisted that step in order to avoid antagonizing Moscow.

🔍 Go deeper: Click on a country in the chart above to see the number of U.S. troops in that individual nation.