The first editions of the Abrams tank were fielded in the early 1980s. Over the decades, the Abrams supply chain has become embedded in communities across the country.General Dynamics estimated in 2011 that there were more than 560 subcontractors throughout the country involved in the Abrams program and that they employed as many as 18,000 people. More than 40 of the companies are in Pennsylvania, according to Sen. Robert Casey, D-Pa., also a staunch backer of continued tank production. A letter signed by 173 Democratic and Republican members of the House last year and sent to then-Defense Secretary Leon Panetta demonstrated the depth of bipartisan support for the Abrams program on Capitol Hill. They chided the Obama administration for neglecting the industrial base and proposing to terminate tank production in the United States for the first time since World War II. Portman, who served as President George W. Bush's budget director before being elected to the Senate, said allowing the line to wither and close would create a financial mess. "People can't sit around for three years on unemployment insurance and wait for the government to come back," Portman said. "That supply chain is going to be much more costly and much more inefficient to create if you mothball the plant." Pete Keating, a General Dynamics spokesman, said the money from Congress is allowing for a stable base of production for the Army, which receives about four tanks a month. With the line open, Lima also can fill international orders, bringing more work to Lima and preserving American jobs, he said. Current foreign customers are Saudi Arabia, which is getting about five tanks a month, and Egypt, which is getting four. Each country pays all of their own costs. That's a "success story during a period of economic pain," Keating said.