Nearly 64,000 U.S. troops stationed in Europe could be deployed to the continent's eastern flank if President Biden makes such a call to counter growing Russian aggression at the border with Ukraine.
The USS Harry S. Truman is already being placed under NATO command for the first time since the end of the Cold War, while 40 warships, 175 aircraft and 90 tanks situated throughout Europe could also be readied for conflict.
Biden has ordered 8,500 U.S.-based troops to stand ready to deploy to Eastern Europe, while military officials have presented him with a plan to send 50,000 more if the security situation deteriorates and Russia launches an invasion into Ukraine.
At the same time, the US told families based at the US embassy in Kiev to go home 'due to the continued threat' of such an attack, the State Department said Sunday.
Though the number fluctuates due to changing withdrawals and deployments, the U.S. had about 175,000 troops stationed abroad as of September 2021. A total of nearly 64,000 of those service members were stationed in Europe.
The U.S. has about 750 military bases across 80 countries.
Command for the U.S.'s 40 warships is based out Italy, and the U.S. has already flexed its muscle to Russia by sending ships to the politically fraught Black Sea.
Germany houses the largest deployment of U.S. troops in Europe, and only Japan and America have more U.S. troops based there. There are 35, 468 U.S. troops in Germany - 21,585 Army, 13,009 Air Force and small numbers of troops from the Marine Corps and Navy.
As the imminent threat of war looms over Europe, it comes as:
The USS Harry S. Truman and its strike group will participate in a NATO exercise in the Mediterranean until February 4; Biden said he and European leaders had 'total unanimity' about the situation in the Ukraine; The White House said NATO has emphasised a desire for a diplomatic solution; Putin discussed a 'strategic partnership' with Cuba in a phone call with President Miguel Díaz-Canel, days after fears were raised that Russia would deploy military to South America; The US and UK have begun withdrawing diplomats from their embassiesin Kiev.
There are 21 U.S. military bases across Germany, with the largest presence at Stuttgart, headquarters of United States European Command (EUCOM) and US Africa Command, and Ramstein, headquarters of US Air Force operations in Europe.
And while Germany previously housed some 5,000 U.S. tanks in the height of the Cold War in 1989, it is now permanent home to none.
The Army temporarily deploys one armored brigade at a time, each on a nine-month rotation. A typical armored brigade is made up of 90 M-1 tanks and 130 Bradley fighting vehicles plus around 18 M-109 self-propelled howitzers.
But there remains a problem: Europe's aging bridges may not be ready for the 68-ton M-1 Abrams tanks. The Army has been struggling to purchase more armored bridge-layers to help these heavy vehicles pass.
The M-1 Abrams has been in use in war zones since 1980, while the Bradley fighting vehicle is a heavily armed and armored troop transporter that launches fire toward enemy lines to provide cover. The Howitzer is a 30-ton gun that can hit targets up to 19 miles away.
And while NATO has a presence of about 130 tanks, including the 90 U.S. vehicles, Russia, even before its recent aggression, kept about 760 tanks within striking distance of NATO's Baltic members.
Ukraine shares a border with four NATO countries: Poland, Slovakia, Hungary and Romania.
Italy has the second highest U.S. presence in Europe, with 12,436 troops, 4,081 belonging to the Army, 4,742 Air Force and 3,497 Navy. The Naples port is the headquarters of the Sixth Fleet, or US Naval Forces Europe-Africa.
The Aviano Air Base is home to two U.S. F-16 fighter jet squadrons. The F-16 is a popular air-to-air combat jet used by 25 air forces.
In the United Kingdom there are 9,576 U.S. troops, almost entirely members of the Air Force with small numbers of service members from other branches.
Spain has 3,423 U.S. troops stationed there, Belgium has 1,143, Greece has 429, Portugal has 259, and Romania has 132. A handful of other nations have a U.S. troop presence smaller
