This is a dispatch from the Afghanistan reporters' "pool," a Pentagon-authorized system that allows a single journalist to file for all accredited news organizations.

MARINE FORWARD OPERATING BASE, southern Afghanistan — The reality of war hadn't set in among many of the 1,300 servicemen stationed at this rough-hewn outpost 70 miles southwest of Kandahar.

That changed quickly in the last 72 hours.

First came Wednesday's helicopter mission to rescue U.S. special operations soldiers and Afghan anti-Taliban fighters wounded by an errant smart bomb dropped by a B-52 near Kandahar.

Then Thursday night, Camp Rhino went on high alert as Marine mortar units fired more than two dozen rounds of flares and high explosives after an undetermined number of enemy forces were detected probing the perimeter of the base. A few hours later, a Marine reconnaissance helicopter was destroyed in a fiery crash that inflicted minor injuries to one of the four-man crew and another Marine on the ground.

Pentagon officials termed the crash of the Huey a "hard landing." It created a huge fireball on the north end of the dirt airstrip that Marine expeditionary units have been using since establishing this base on Nov. 26. The injured men were not identified.

The cause of the crash is under investigation, and it was unclear whether mechanical failure, dusty desert conditions or gunfire were responsible. But Capt. Stewart Upton, a Marine spokesman here, said he was "ninety-nine percent sure" the helicopter was not brought down by enemy fire.

Wednesday's off-course bomb killed three U.S. Special Forces soldiers and wounded about 20 others. Six Afghan anti-Taliban fighters also were killed in the blast. Twenty Afghan fighters, ranging in age from their teens to early 60s, were wounded.

With several companies of Marines stationed in freshly-dug fighting holes ringing the perimeter of the base, air crews bivouacked near helicopters and others out on long range "hunter-killer" missions in heavily armed Humvees and other fighting vehicles, many Marines didn't learn of the dead and wounded until Thursday.

Pilots and crewmembers manning the CH-53 Super Stallions and Cobra helicopter gunships that provided protection on Wednesday's hour-long rescue flight said they were a bit nervous about a daylight mission over enemy territory. "Knowing you are going into bad-guy country makes your heart skip a beat," said Staff Sgt. Bryon Edgecombe, 26, a Super Stallion crew chief.

Two Navy surgical teams of about a dozen doctors, nurses and specialists treated the wounded for broken bones and shrapnel wounds in two large medical tents here.

"None of the Afghans looked angry over what had happened or complained; they were very stoic and appeared to have a high tolerance for pain," said Steve Temerlin, a Navy emergency medical physician.

This is the first combat mission for Temerlin, 48, who joined the Navy in 1990 after 10 years in private practice.

"It's definitely more serious today," Temerlin said. "But there's a certain amount of assurance that yes, we can do this."

Aside from the angst of seeing the dead and wounded, the mood among many at the base was tempered by the fact that today is the 60th anniversary of Japan's attack on Pearl Harbor.

"To be here in Afghanistan on Dec. 7, you can’t help but reflect what happened back then," Capt. Dave Romley said. "But all of the Marines out here are very proud to be American instruments of justice."

To most of the young Marines here, Pearl Harbor is little more than a note in history, remembered more by last year's movie by the same name.

"I can see the connection between then and now," said Sgt. Tony Walker, a 26-year-old communications specialist from Scottsdale, Ariz., assigned to the staff of task force leader Gen. James Mattis. "If I was the same age back then, I'd probably be doing the same thing I'm doing now, serving in the Marines."

So far, there's been little payback by the Marines against Usama bin Laden and elements of his Al Qaeda terrorist network.

Hunter-killer teams have expanded their patrol areas near Lashkar Gah, a city of about 50,000 some 90 miles west of Kandahar. It's believed some Taliban tanks, armored vehicles and an undetermined number of fighters are holed-up in the area.

"They haven’t destroyed anything significant yet," Romley said.

Amid the increasing danger, there have been some lighter moments at this base teeming with soldiers from the Marine's 15th and 26th expeditionary units, an undisclosed number of special operations forces and about 100 newly arrived troops from Australia's special forces.

Two nights ago, forward observers on the perimeters of the base spotted an intruder. Shots were fired as Marines poured out onto the line. But it turned out to be just a wayward camel.

"I don't think they hit it," Romley said. "But there was some concern that it may have been strapped with explosives."

The 1.2-mile-long dirt landing strip atop a dry lake bed is used almost exclusively under the cover of nightfall. C-130 and giant C-17 cargo jets bring several sorties of supplies and materials into the expanding base here. "We didn’t want the camel near the runway," Romley said.