The U.S. Senate will likely vote today on whether to strip funds for extra C-17 cargo airlifters from next year’s Pentagon spending bill. This decision would permanently eliminate the United States’ only remaining military wide-body aircraft production line. Members are rightly skeptical about airlift requirements in light of recent announcements to again grow the Army by 23,000 troops. More soldiers need more lift to get themselves and their equipment overseas to win the nation’s wars. The justifications are not holding up to scrutiny, and the C-17 will more than likely live to fly another day.

Soldiers and Marines engaged in combat rely on the C-17 Globemaster III, C-5 Galaxy, and C-130 Hercules aircraft to perform the inter-theater airlift mission. Along with traditional airlift roles, expanded ground operations as part of global counterterrorism and counterinsurgency missions have placed a renewed emphasis on the airlift mission.

Strategic airlift has become so important that “preserving global reach in the air,” specifically by the C-17 aircraft, was singled out by President Obama as a defense priority on his presidential-campaign website and then again on the White House website after his inauguration. In direct contradiction to this stated priority, Obama’s first military budget request recommends ending production of the C-17 at 205 aircraft.

The C-17 carries 169,000 pounds of equipment, including the Abrams tank and Apache helicopter. Although it comprises 60 percent of the airlift fleet, it flies more than 80 percent of all strategic airlift missions. It has been used in military operations everywhere from Bosnia and Kosovo to Iraq and Afghanistan.

The C-17 benefits from its ability to operate from austere airfields, including dirt runways, making it invaluable in the tactical airlift role as well. Following an increase in attacks on U.S. and coalition convoys in Iraq in 2004, for instance, the C-17 was used alongside the C-130 to relieve 350 vehicles per week. This summer, two C-17s were used to deliver aid to Pakistan as part of a humanitarian-relief effort. The C-17’s performance characteristics are also significantly better than those of other cargo-transport aircraft.

Secretary Gates has repeatedly emphasized that he wants a force capable of fighting counterinsurgency operations. If that is indeed the case, then ending the C-17 line makes no sense. Given the danger of rockets, improvised explosive devices, and guerrilla attacks on truck convoys overseas, the C-17 has become the preferred means for moving men and materiel in places like Afghanistan.

Fresh off a victory to kill the F-22, some in Congress may think permanently closing the C-17 line will be easy. But this is the most popular program on the Hill for many good reasons. The C-17 is built by more than 30,000 workers and supported by an additional 700 suppliers. Canada, the United Kingdom, and Qatar have already placed orders, and the United Arab Emirates has entered negotiations to purchase the aircraft. However, if Congress does not fund the procurement of additional C-17s, this line will begin closing this year due to the 34-month supplier lead time to build one.

The costs of choosing to restart the line after it has already been closed are immense. A 2006 Department of Commerce study found “the cost of closing down the Long Beach [California] site, restarting at a new site in the United States, and then having to close it down again after a short production run — is about $5.7 billion.”

Furthermore, the justification that the Pentagon “doesn’t want more of something” only goes so far in Congress. This is because members have a long history of reversing decisions based purely on budget constraints that were later praised by the military. The Air Force wanted to kill the F-117 but was forced to buy more. This aircraft later was critical to establishing air dominance over Iraq in Desert Storm. Same goes for the continuation of the V-22 Osprey program, and prohibition against retiring U-2s and B-52s, all platforms which are force multipliers in Iraq and Afghanistan today.

But most importantly, members recognize that as the U.S. Army is set to grow again next year. More troops need more lift capability. It looks like Congress is wise to keep its options open and buy ten additional C-17s in the 2010 defense appropriations bill.

— Mackenzie Eaglen is research fellow for National Security Studies at the Heritage Foundation.