KABUL, Afghanistan — The loss of elite American troops to a Taliban rocket-propelled grenade is a window on the war to come – focused increasingly on the type of special operations the troops were pursuing when their helicopter crashed.

The U.S. military released new details Monday about the crash in the Tangi Valley, a dangerous area of Wardak province on the doorstep of the Afghan capital. The 30 U.S. troops, seven Afghan commandos and an Afghan interpreter who died were taking part in one of thousands of nighttime operations conducted annually across the nation.

The sheer number of these missions is evidence that progress in the nearly decade-long war depends more on efforts to kill or capture insurgents than the overarching strategy of building support for the Afghan government at grassroots levels. And these missions will take on relatively more importance as troop levels decline.

Saturday’s crash of the CH-47 Chinook helicopter was deadliest single loss for U.S. forces in the war and raised anew questions in the United States about why U.S. troops are still fighting the unpopular conflict.

U.S. leaders vowed on Monday not to let the loss rewrite the war strategy.

“We will press on and we will succeed,” President Obama said at the White House.

In Kabul, German Brig. Gen. Carsten Jacobson, a spokesman for the U.S.-led coalition, said troops continued Monday to recover every last piece of the helicopter and that no one was being allowed in or out of the heavily secured crash site during the investigation.

Pentagon officials said two C-17 aircraft carrying the remains of U.S. and Afghan troops killed in the crash left Afghanistan Monday night en route to Dover Air Force Base in Delaware. They said that there will be no public media coverage at the Dover base during the ceremony that typically takes place when the bodies of fallen troops arrive because the badly damaged remains are mingled and still being identified.

Many of the Americans who died were members of the Navy’s SEAL Team Six, the unit that conducted the raid that killed al-Qaida leader Osama bin Laden at his hideout in Pakistan. But none of the SEALs killed in the crash took part in the bin Laden mission. The official name of the SEAL team is the Naval Special Warfare Development Group.

The troops, who were packed into the twin-rotor chopper, crashed while on a mission that targeted a Taliban leader in the mountainous and heavily forested Sayd Abad district of Wardak, the coalition said. The helicopter was transporting them to the scene of an ongoing fight between coalition forces and insurgents.

Ali Ahmad Khashai, deputy governor of Wardak province, said insurgents frequently move through the valley.

“This area concerns us because many attacks in Wardak are organized and planned in Tangi,” he said. “The enemy is active and the (military) operations have not been effective, unfortunately, because it is between three provinces. Maybe there are mountains and forests between these provinces that no one is taking responsibility for.”

The Taliban claimed they downed the helicopter with a rocket. U.S. military officials said the helicopter was hit as it was trying to land. Although the investigation has not yet been completeted, the coalition said in a statement that the “helicopter was reportedly fired on by an insurgent rocket-propelled grenade.”

Coalition troops on the ground searching for the Taliban leader saw several insurgents armed with rocket-propelled grenades and AK-47 assault rifles moving through the area, the coalition said. U.S. officials said the ground force was made up of U.S. Army Rangers, who regularly work with the SEALs. During the gunbattle, the ground force called for assistance.

“Those additional personnel were inbound to the scene when the CH-47 carrying them crashed, killing all on board,” the coalition said.

A U.S. official said the force was acting as what is called an “Immediate Reaction Force,” flying in to provide extra firepower to subdue a target, rather than a Quick Reaction Force, which comes in to stage a rescue. But multiple officials say hard questions are being asked about whether the target merited risking so many elite troops.

More U.S. special operations troops are in Afghanistan – about 10,000 – than in any other theater. The forces, often joined by Afghan troops, are among the most effective weapons in the coalition’s arsenal, conducting surveillance, infiltration and night raids on the compounds of suspected insurgents.

From April to July, 2,832 special operations raids captured 2,941 insurgents and killed 834 militants – twice as many as over the same period last year, according to the coalition.

Special operations troops are expected to have a significant role as American forces begin drawing down as part of Obama’s plan to bring 10,000 U.S. troops home by year’s end and as many as 23,000 more by September 2012.