No, the Pentagon is not the center for foreign policy in the US. The Pentagon is the headquarters for the US Department of Defense (DOD). The mission of DOD is to provide the military forces needed to deter war and to protect the security of our country.
Basically, Foreign policy of the US is the split amongst different governmental structures, involving the President, the Department of State, Congress, the courts and members of the US DOD. “America’s foreign policy is the expression of its goals in the world and of how it proposes to achieve them, a reflection of the nation’s interests and a guideline of how to interact with other countries. “