Trump says he's pulling U.S. troops from Germany. Does it matter?

Trump is once again threatening NATO allies. What would a reduction of U.S. troops in Germany mean for security and the U.S. military? Today, about 36,000 U.S. troops are stationed in Germany, and they’re a key part of the U.S. military ecosystem and the NATO alliance. Now, President Trump plans to reduce that number. Trump has grown increasingly and publicly frustrated with NATO allies. This time he’s taking it out on German Chancellor Friedrich Merz, who said the U.S. has been humiliated by Iran. Among the many questions raised by this: What are U.S. troops doing in Germany anyway?