When the U.S. counterterrorism operations against the Abu Sayyaf Group, the Philippines-based al Qaeda affiliate, kicked off in late 2001, the Bush administration dubbed it the "Second Front" in the War on Terror. Today, it's more like the "Forgotten Front."

But the lack of notoriety isn't necessarily a bad thing. The joint U.S.-Philippine counterterror campaign in the southern Philippines is going pretty darn well after 5½ years. Indeed, some experts tout the "Operation Enduring Freedom-Philippines" campaign as the most successful counterterrorism/insurgency effort of the post-9/11 period.

Abu Sayyaf (ASG) is hardly a household name. But the Muslim terrorist group has plenty of terrorist street cred: Osama bin Laden's brother-in-law founded it, along with other jihadists who had fought the Soviets in Afghanistan.

The ASG also had ties to al Qaeda bigs Ramzi Yousef and his uncle Khalid Sheikh Mohammed, who both spent time in the Philippines and were involved in the 1993 World Trade Center bombing, Operation "Bojinka" (an unsuccessful 1995 bombing of 11 airliners out of Manila) and 9/11.

Its stated goal is to establish an independent Islamic state in the southern Philippines. But some believe its project extends to all of Muslim Southeast Asia.

The ASG engages in kidnappings (for ransom), bombings, beheadings, assassinations and even extortion of Filipinos and foreigners (especially tourists). U.S. citizens and soldiers number among its victims.

In 2004, it bombed a ferry in Manila Bay, killing more than 100. The same year, an ASG cell was broken up while targeting the U.S. embassy in Manila.

ASG also has ties to al Qaeda's pan-Southeast Asian terror powerhouse, Jemaah Islamiya - the group that killed nearly 200 in the Bali bombing in 2002. It also gets support from a range of Middle East extremists.

The good news?

U.S.-Philippine operations have significantly weakened the terrorist group. Philippines forces have killed two senior ASG commanders since last December. One was sold out by an ASG member-turned-informant, motivated by the State Department's rewards program.

Once 2,000 fighters strong, ASG's been whittled down to around 200 to 300 today. As a result, its trademark bus and local market bombings have dropped off, as has its once-lucrative kidnapping practice. The threat has clearly receded.

But why has this operation shown success?

Indirect Approach: The United States isn't doing the fighting. Philippine armed forces are - 15,000 of them, with 300 U.S. troops "advising and assisting." Our forces are not only teaching counterinsurgency tactics and nighttime operations, they're instructing the Filipinos to collect, analyze and fuse intelligence - even when it comes from a high-tech U.S. Predator drone.

This puts the local Philippine forces in the lead - and gives them the training and battlefield experience to provide a lasting capability that will endure long after the U.S. troops head home.

Hearts and Minds: A significant effort has been made to win local hearts and minds. U.S. and Philippine civil-affairs, humanitarian aid and exercises are helping separate the ASG from the general population. During regular joint "Balikatan" military exercises, Americans and Filipinos build roads, schools, water plants and piers that allow locals to build a better future for themselves - and instill trust and confidence in Manila.

Defense Reform: In 2002, the Pentagon undertook a bilateral program to help the Philippines identify much-needed defense reforms and boost our ally's armed forces' professionalization.

That extends to unsexy but vital areas such as maintenance and logistics. In 2001, Philippine military helicopters were mission-ready just 15 percent of the time. Today, those helos are ready for counterinsurgency 80 percent of the time.

Stick-to-itiveness: Despite up and downs in the bilateral relationship (especially when Philippine President Gloria Macapagal Arroyo withdrew forces from Iraq), Washington stuck to eliminating the ASG. Resolve makes a difference.

Is this a model for U.S. counterterrorism operations elsewhere? Maybe; maybe not. Some of the approach is similar, but the Philippines is, without a doubt, unique. It's blessed with a better (more popular and stable) government than Iraq or Afghanistan - and isn't cursed with the same sort of poisonous neighbors.

There is no cookie-cutter approach to fighting terrorism, but some lessons of the Philippines might be applied elsewhere. Indeed, it should be an imperative.