Answer:
Authority to summon military and civilian leaders to testify before congressional committees
Step-by-step explanation:
The Senate plays an important role in US international relations. The US constitution allows the president to make treaties but he needs to submit it to the Senate for its approval. The senate must approve it with two third vote. The Senate Foreign Relations committee plays an important role in this and it assesses the nominees to the state department.
Section two of the Article 2 of the US constitution empowers the senate to advise and gives its consent to the ratification of the treaties which have been agreed and negotiated by the president. It also approve defence appropriations.
It also have the authority to empower the standing committees to make witnesses testify for the subjects under its jurisdiction but in case of military appointments not all appointments are required to be confirmed by the Senate.