You are subject to all laws in that country. You can be detained without cause. You can be denied legal representation. Depending on their relationship with the US, you may be able to call the embassy. The embassy may be allowed to visit you, but no guarantee. They may leverage you with the US for funding, exchange for One of their prisoners, or recognition of their new regime if it is a coup. In the end if you are released, it may be labeled as a misunderstanding and you would have no civil legal recourse. .