They are a legacy of World War II and a symbol of US commitment to protecting its European allies.
But United States military forces stationed in Germany are reportedly going to be significantly reduced.
US President Donald Trump plans to pull out 9,500 American soldiers by September, reducing the total number to 25,000.
Troops will either be deployed elsewhere or brought home.
It is being seen as the latest twist in relations between Washington and Berlin.
Tensions between the two sides have been strained over a number of disagreements, but defence spending has been of particular concern for Trump.
He has repeatedly pressed Germany to increase its military budget and has criticised NATO allies for relying on the US to shoulder the costs of maintaining the alliance.
But why is this move coming now and should US allies and NATO be concerned?
Presenter: Laura Brennan
Andrew Bacevich - US military historian and professor emeritus of international relations and history at Boston University
Ulrich Brueckner - political analyst and professor in european studies at Stanford University, Berlin
Pavel Felgenhauer - defence analyst
Source: Al Jazeera News