AL-TAQADDUM, Iraq — The war here smells like diesel fumes and nostalgia.

In the distance, there is an explosion, a single thud that has the Marines of Baker Company, 1st Battalion, 7th Marines, on their radios trying to figure out what it was. ‘‘Iraqi artillery, I think,’’ the Marine on Post Eight decides. It is dark and getting cold and the infantryman on Post Eight has been here since October.

Post Eight and its fellow line of fortifications is just adjacent to Al-Taqaddum’s tarmac and makes up one of the borders of the American camp, called Camp Manion, after a Marine lieutenant killed by a sniper in Iraq in 2007. The camp is an outpost within an outpost, an island in the middle of the now Iraqi-controlled Al-Taqaddum airbase, where a small contingent of Marines, soldiers, and Special Forces help train Iraqi troops to fight the Islamic State.

While some of the fortifications around the American part of the base are holdovers from years past, most have been flown in and constructed in the last year. When the Iraq war ended in 2011, the United States tore down almost all of its bases in the country. Now, it is rebuilding them.

Less than a decade ago, at the height the conflict’s last iteration here, Al-Taqaddum’s mess hall was renowned across al-Anbar province. A five-star dining facility tucked between the restive cities of Fallujah and Ramadi, Al-Taqaddum had a spinning glass case of self-serve desserts that has since become an object of legend — whispered about wherever Americans find themselves at war.

But now it is no more, erased since the last troops pulled out in 2011. The current mess hall is a shell of its former self, a drafty warehouse with walls covered in a patchwork of tarps and a dessert selection relegated to cardboard boxes filled with Pop-Tarts.

Just a few hundred yards away from Al-Taqaddum’s now-rudimentary dining facility is the wooden command post for Baker Company. Inside, among many things needed to run an infantry company effectively, is a plastic Christmas tree bought from Home Depot and a cache of socks sent from the Socks for Heroes organization.

The Christmas tree is a new addition to the company. Covered in tinsel and ornaments and lights, the tree could be lit, but the Marines have decided their one power adapter should remain attached to the coffee machine. Their first sergeant, however, whose parents sent the tree and its accompanying decorations, has plans to light the tree on Christmas.

‘‘It’ll be like kind of a ceremony,’’ he said, and the sergeant who leads the company’s engineer detachment has assured him it will work.

Baker Company is tasked with security for all of Al-Taqaddum, and the Marines take turns rotating between patrolling inside the perimeter, standing post, and manning the quick-reaction force, or QRF. The QRF stays in a room next to the operations center for 24 hours at a time. There, they eat and sleep and wait for something to happen. Often, nothing does, but recently Marines from Baker Company and their medical personnel, known as Navy corpsmen, have responded to Iraqi casualties brought to Al-Taqaddum’s entry control point. Most of the casualties, Marines from Baker Company say, have come from the Iraqi military’s ongoing battle to retake the key city of Ramadi.

Aside from the war, the Iraqi casualties, and the Christmas tree, the pressing issue for Baker Company is the new “Star Wars’’ movie, which many would like to see soon. With the Internet readily available in the Forever War, there is little hope among the Marines that they can make it until the end of their deployment without stumbling on a spoiler.

But one Marine — who knows a guy, who knows a guy — thought he might be able to get his hands on a bootleg copy from the Iraqis. The effort is a long shot, but now urgent, since the Marines heard that one of their fellow companies, Weapons Company, stationed about 100 miles to the northwest at Al-Asad airbase, had secured a screening.

‘‘If we watch it we could make costumes,’’ one Marine from Baker Company said. ‘‘You know, we could turn Hesco cloth into Jedi robes.’’

Weapons Company from 1st Battalion, 7th Marines, of Twentynine Palms, Calif., indeed plans to make a strong attendance at Al-Asad’s multiple screenings of ‘‘The Force Awakens’’ on Dec. 28.

The group carries out many of the same tasks as Baker Company, but they are stationed at Camp Havoc, another ‘‘base within a base’’ where they patrol the perimeter of Al-Asad’s airfield and provide security as Danish troops help train elements of the Iraqi Army’s 7th Division.