Answer:
The President
Step-by-step explanation:
Section 2 of Article 2 of the US Constitution states the following:
"The President shall be commander in chief of the Army and Navy of the United States, and of the militia of the several states when called into the actual service of the United States (...)."
Although the Constitution gives Congress the power to declare war, it is the President the one that can command the U.S. Armed Forces when in wartime. As a Commander in chief of the U.S. Armed Forces, the president has the powers to command and control where military troops and ships should go, where they should be stationed, how they must be organized and what weapons they should use and when they must fight in wartime.