WASHINGTON — The unrest engulfing Arab streets and threatening authoritarian governments in the Mideast is complicating U.S. counterterrorism efforts.

Experts says that U.S. counterterrorism officials need to move quickly to firm up relationships with veteran Mideast intelligence and security services in the aftermath of momentous changes. They say confusion over who will take the reins of power could hamper quick decision-making.

The experts question whether over the long term the U.S. will be able to work closely against al-Qaida and other terrorist organizations if important U.S. allies cede power to Islamist groups, such as Egypt's Muslim Brotherhood.

The uncertainty comes amid growing American concerns following a string of failed attacks plotted in Yemen and al-Qaida's home base inside Pakistan.