Shortly after Russia deployed an air wing to western Syria in order to help save the embattled regime of Syrian president Bashar Al Assad,...

Shortly after Russia deployed an air wing to western Syria in order to help save the embattled regime of Syrian president Bashar Al Assad, Moscow asked the United States to supply rescue helicopters to keep watch over Russian aviators.

The Pentagon said no, according to a brief story by Air Force magazine’s Brian Everstine, reporting from the Air Force Association’s symposium in Orlando. Lt. Gen. Charles Brown, the commander of Air Forces Central Command, recommended against helping because “the U.S. has just enough resources to take care of itself,” according to Everstine.

Rescue forces are rare and specialized. The Air Force’s roughly 100 HH-60G helicopters and their pararescue jumpers are America’s main rescue resource. The Marines’ aircraft-recovery units flying in MV-22B tiltrotors can perform a rescue function, too, as can U.S. Special Operations Forces with their own H-47, H-60 and V-22 rotorcraft.

Air Force HH-60Gs are in Turkey, Marine MV-22Bs are in Kuwait and Special Operations Command has undoubtedly deployed its own aircraft to the Middle East for operations over Syria. But on a good day, commanders might have just a handful of rescue copters to cover potentially hundreds of aircrew flying over enemy territory.

As it turns out, Russia really did need rescuers. On Nov. 24, Turkish air force F-16s shot down a Russian Su-24 bomber after the Russian plane allegedly briefly strayed into Turkish airspace. The two-man Su-24 crew ejected over Syria. Rebels on the ground gunned down one crewman. Two Russian Mi-8 helicopters carrying Russian marines and Syrian and Hezbollah commandos flew to retrieve the surviving pilot.

Rebels attacked the copters as they landed, damaging one rotorcraft and killing a marine. The surviving rescuers retrieved the Su-24 pilot. Later, rebels destroyed the damaged Mi-8, which the Russians had abandoned, with a U.S.-made TOW missile.

Besides the matter of resourcing, there are good policy reasons why the United States would not offer direct assistance to Russia’s campaign in Syria. Despite claiming that its forces are in Syria to help defeat Islamic State — a goal that, in theory, Washington could get behind — in reality Russian air strikes frequently target U.S.-backed rebels and unarmed civilians.