After surviving numerous attempts to scrap it from the U.S. defense budget over the last few years, the 40-year-old A-10, a warplane built during the Cold War to destroy Soviet tanks, is back on the front lines of what could become a confrontation between NATO and the Russian army. The plane is about to take part in long-term exercises in Romania designed to counter Russian moves in the region.

The exercise is just one of many over the last five months in which the plane, popular with airmen but not with top generals focused on saving money, has been involved on Russia's doorstep. A-10s have been sent to Poland and Germany, as well as in the Middle East, where they are taking part in the fight in Iraq against the Islamic State group.

According to Romanian press reports, four A-10s have already arrived at the Romanian air force base in Campia Turzii, near the city of Cluj-Napoca in central Romania. A further eight are expected in the coming days. The airbase is just 200 km (120 miles) from the border with Ukraine, which is engaged in a war with Russian-backed separatists.  

The technical term for what the Warthog, as the plane is known, is doing in Eastern Europe is providing a "theater security package," in other words air cover along with other U.S. and NATO planes for ground troops taking part in exercises there.  

“There's a lot of exercising going out there, and we intend to support the Army to the maximum extent possible in this endeavor," said Gen. Frank Gorenc, commander of U.S. air forces in Europe. "This [theater security package], particularly in the form of the A-10, is going to be very, very useful."

Built between 1972 and 1984, the slow, heavily armed A-10, made to fly low and hunt armored vehicles, did not see combat until the first Gulf War in 1991, when it destroyed more than 900 Iraqi tanks, 2,000 other military vehicles and around 1,200 artillery pieces. The aircraft went on to have similar success during the Balkans conflict in the mid-1990s and throughout the wars in Iraq and Afghanistan, where it was deployed with excellent results against the Taliban and al Qaeda. 

Ungainly and devoid of much of the latest technology found on supersonic fighters, the A-10 made a name for itself as an excellent plane for a specialty known as close air support, or hitting enemies near friendly troops with precise strikes. That has helped it survive the end of the Cold War, which had originally been the plane's sole reason to exist -- it was supposed to hunt and destroy Soviet tanks rolling across Central Europe. Plans to scrap it years ago in favor of the F-16 were shelved. 

But despite its combat successes and Gorenc’s words regarding its usefulness, it remains on the chopping block, was saved from being retired this year only thanks to a stopgap measure, and continues to divide congressional leaders and the military brass. 

Under the current defense budget, which is subject to forced sequestration starting in 2016, the military is expected to make adjustments to deal with automatic budget cuts. For the U.S. Air Force, retiring its almost 300 A-10s would save $4 billion over five years. It would then be replaced, says the USAF, by the new F-35, a plane that some military experts warn is not a good fit for the job. 

Over the last few years, however, Congress has repeatedly saved the aircraft from those cuts and frustrated Air Force leaders, who say the mechanics who now maintain the A-10 fleet must soon start retraining to service the F-35. This year looks to be no different.

Sen. Kelly Ayotte, a New Hampshire Republican whose husband flew A-10s on combat missions in Iraq, has long been the leader of congressional campaigns to protect the aircraft. She has written the leaders of the Senate Armed Services and Appropriations Committees to ensure that neither make moves to scrap the aircraft, and that they pass legislation authorizing $737 million to fund it in 2016. "When we send our troops into harm’s way, we have a solemn obligation to ensure that they have the very best support possible so they can accomplish their missions and return home safely," said a letter Friday from the group led by Ayotte. "Unfortunately, the Air Force is again pursuing its premature, misguided and dangerous divestment of the A-10.”

Not only does the group of politicians led by Ayotte want to save the aircraft for another year, it wants the 2016 defense spending bill to specifically prohibit any moves to get rid of it until a fully capable replacement is available. That law would be similar to legislation that requires the U.S. Navy to have 11 aircraft carriers at all times.

The A-10 backers say the F-35, which will cost in excess of $1 trillion and is not expected to become fully operational until 2021, is not yet a fitting replacement for the heavily armored and accurate old Warthog. Soldiers are known to be fans of the aircraft and affectionately refer to it as the "Hog."

The letter, which is addressed among others to Armed Services Committee Chairman John McCain, R-Ariz., another champion of the A-10 among the Senate's top ranks, does concede that in years to come the F-35 may be able to offer the same close air support that the A-10 does, but that those capabilities “remain to be seen.”  

"We still need CAS [close air support] aircraft that can fly low and slow, beneath bad weather, close enough to the point of ground combat, and survive," the letter said. “The Air Force has not persuaded us that it can prematurely divest the A-10 — our nation’s most combat-effective and cost-efficient [CAS] aircraft — without putting our ground troops in serious additional danger.”

The letter was also signed by nine other Republican senators, several from states which house A-10 bases and would stand to lose out economically if the plane were scrapped.