Secretary of Defense Robert Gates just returned from a visit to China after the recent restoration of military ties between the two countries. While he was there, China’s military leaders unveiled a new stealth fighter jet.

The Chengdu J-20 prototype of a future stealth fifth-generation multirole aircraft clearly caught the attention of U.S. defense officials. Secretary Gates told reporters that the Chinese “clearly have potential to put some of our capabilities at risk,” and while the U.S. military has known that China sought a stealth fighter, the J-20’s development outpaced intelligence estimates.

As China builds up its military at a breakneck pace, the traditional margins of U.S. technological military superiority are declining across the board. These long-held “margins” are ingredients in U.S. military supremacy that have ensured that our forces are never in a fair fight.

Our most capable fighters—the F-22 Raptor and F-35 Joint Strike Fighter—are outstanding, but the Pentagon is not planning to buy enough of either. For the first time in history, the U.S. military has no manned aircraft under development. The highly skilled defense workforce that designs and builds these superior fighters is at risk. While the U.S. has only one fifth-generation fighter in production today, China and Russia have a combined twelve fighter and bomber lines open for business.

The modernization plans of all the armed forces to replace their legacy fleets with next-generation equipment have been dramatically cut the past two years, most notably the U.S. Air Force. These cuts will further reduce the U.S. military technological edge against defense investments by other countries. That doesn’t mean the United States will necessarily be fighting some peer competitor that may not exist today. Rather, what Washington chooses to invest or not invest in will provide incentive for others to build up where the United States is pulling back.

Congress must ensure that the U.S. military acquires adequate numbers of fifth-generation fighters in order to give tomorrow’s forces the same air supremacy that has ensured that no single soldier or Marine has lost his life due to a threat from the air in over a half-century.