They were fast friends. And when they found a common cause -- online -- they began to consider themselves as something more: brothers in arms. The Web led them into a worldwide web of terror.

No, we're not talking about this month's story of five young men from Virginia who were picked up on terrorism charges in Sargodha, Pakistan. This story goes back years, to two young men from Atlanta.

Arrested in 2006, Ehsanul Islam Sadequee and Syed Haris Ahmed were recently sentenced on a slew of terrorism-related charges. Theirs is a textbook case of domestic radicalization. They spent hours online chatting and watching videos produced by terrorist groups.

Then they started to mimic their "heroes." In 2004, they began practicing paramilitary techniques, training with paintball guns. Then the pair started reaching out to others interested in Islamist-inspired violence.

On the Internet, they hooked up with a group in Canada and took a bus there to spend a week with their new friends. One of the Canadians was later arrested as part of the "Toronto 18," a cell that planned to bomb the parliament building in Ottawa.

In 2005, Ahmed went to Pakistan where he met with a known Taliban operative. Sadequee trekked to Bangladesh and joined a terrorist group called al Qaeda in Northern Europe. Later he was arrested in Sarajevo with a cache of weapons, including, according to the FBI, "over 20 pounds of plastic explosives, a suicide belt with detonator, a firearm with a silencer."

The tale of Northern Virginia's five terrorism tourists picked up in Pakistan was strikingly familiar. They, too, had spent a lot of time online scrolling through Facebook, scanning YouTube and trying to contact extremist groups on the Internet. They also ended up in Pakistan, caught in the act of trying to link up with a recruiter who had ties to the Taliban and al Qaeda.

There was, however, a big difference in the two cases. Sadequee and Ahmed had been under investigation for some time. At trial, the government presented a bucketload of evidence detailing Sadequee and Ahmed's big adventure from recruiting on extremist Web forums to casing potential targets in Washington, D.C.

They were not the only ones caught in the act. Last month, prosecutors indicted eight men on charges of recruiting Somali immigrants in the United States to join al Shabaab, a terrorist group based in Africa with links to al Qaeda.

In contrast, law enforcement knew nothing about the five young men from Virginia until just after Thanksgiving, when they were reported missing.

Stopping homegrown radicals before they start killing is always the better option.

Before the al Shabaab recruiting cell was taken down, it shipped a number of would-be teenage terrorists overseas. Five died fighting for militias in Somalia. One blew himself up in a suicide attack. If the Northern Virginia Five had not been picked up by the Pakistanis, they too would have likely come to a bad end and taken a lot of innocents with them.

The lesson of the Sadequee and Ahmed case is that attentive and proactive law enforcement works. Effective counterterrorism investigations can stop terrorist plots before they come to fruition.

To dodge the charge of being "soft on terrorism," lawmakers tacked a 60-day extension of the authorities into the defense appropriations bill. This strategy allows Congress to kick the question of the Patriot Act down the road. Now lawmakers can deal with it next year, rather than have constituents trouble them about it while they're home during Christmas recess.

The problem is that there is still a faction in Congress that wants to water down these proven tools of counterterrorism law enforcement. And, so far, the White House and liberal leaders in both chambers of Congress are unwilling to just say "No."

The authorities in the Patriot Act are exactly what's needed to find and stop people like Sadequee and Ahmed. If our political leaders are serious about preventing terrorist attacks in the U.S., they need to stop the delaying and renew the crime-stopping, lifesaving provisions of the act.

James Jay Carafano, Ph.D., is Assistant Director of the Kathryn and Shelby Cullom Davis Institute for International Studies and Senior Research Fellow for National Security and Homeland Security in the Douglas and Sarah Allison Center for Foreign Policy Studies at The Heritage Foundation.