Early this morning, news broke of an attempted terrorist attack against U.S. military targets in Afghanistan.

A federal complaint unsealed yesterday alleges that four men—all U.S. citizens or permanent residents—were engaged in an active plan to carry out “violent jihad” and target U.S. government facilities in Afghanistan.

From the news reports, it appears that the cell was led by Sohiel Omar Kabir, a naturalized U.S. citizen and former member of the U.S. Air Force. Kabir used the writings and works of radical Islamist Anwar al-Awlaki to inspire and recruit 23-year-old Ralph Deleon of Ontario and 21-year-old Miguel Alejandro Santana Vidriales.

The two men, later joined by U.S. citizen David Gojali, had sold all of their belongings and made arrangements to depart for Afghanistan in mid-November. Kabir, already in Afghanistan, helped to make the arrangements for the other men.

According to the federal complaint, once in Afghanistan, the men planned to join “the students” (the Taliban) before joining “the professors” (al-Qaeda). The men appear to have been preparing to join a Taliban training camp by practicing at local gun ranges and paintball fields in Southern California.

While the full details are still unfolding, the plot appears to have been foiled by FBI agents who infiltrated online conversations between the men and monitored Skype conversations between Kabir and the others.

This plot to attack U.S. interests overseas is just the latest successful effort of the U.S. intelligence community to thwart terrorist attacks long before the public or U.S. interests are put in danger.

Indeed, of the 53 foiled terrorist plots against the American homeland since 9/11, 45 were thwarted by U.S. law enforcement and intelligence, the most recent of which involved an attempt to detonate a bomb outside the Federal Reserve Bank in Lower Manhattan.

Their continued success, however, requires that vital counterterrorism and intelligence tools are maintained. Support for important investigative tools, such as the PATRIOT Act and the Foreign Intelligence Surveillance Act (FISA), is essential to maintaining the security of the U.S. and combating terrorist threats.

FISA authorizes electronic surveillance within certain legal limits, while key provisions of the PATRIOT Act—such as the roving surveillance authority and business records provision—have proven essential to thwarting terrorist plots.

Yet these resources require reauthorization every year. Indeed, the Foreign Intelligence Surveillance Amendments Act of 2008 will expire at the end of this year if Congress does not act.

Today’s news should serve as a reminder of the continued threat of terrorism both at home and abroad and the need to remain vigilant. As we draw down the military in Afghanistan, we must keep up our guard—and our intelligence capabilities.