The threat perceptions of many Arab states aligned with the United States have changed significantly as a result of such dramatic events as the 2011 U.S. military withdrawal from Iraq, the emergence and then fading of the Arab Spring, the rise of Iranian power and Tehran's nuclear agreement with key world powers, the Egyptian revolution and counterrevolution, and the development of civil wars in Syria, Iraq, Yemen, and Libya. There have also been some notable differences that have developed between the United States and its Arab allies over how to address these issues and most especially Iranian regional ambitions. This report considers ways in which the United States might react to these events with a specific focus on military coordination and support to friendly Arab countries. It notes that a variety of U.S. officials remain intensely committed to a strong effort to work with Arab allies and to convince them that the United States will not abandon them or downgrade the importance of their security concerns.