A group of seven Democratic senators on Tuesday called on the president to cancel the Air Force’s nuclear air-launched cruise missile program, the Long Range Standoff (LRSO) weapon.

In a Dec. 14 letter, Sens. Edward J. Markey (D-Mass.), Dianne Feinstein (D-Calif.), Jeff Merkley (D-Ore.), Bernie Sanders (I-Vt.), Patrick Leahy (D-Vt.), Al Franken (D-Minn.) and Ron Wyden (D-Ore.) said the LRSO would play a destabilizing role in national security.

Like the legacy AGM-86 Air Launched Cruise Missile (ALCM), LRSO would come in nuclear and conventional variants that that would be indistinguishable, thus raising the risk of miscalculation when a conventional cruise missile is deployed, the senators said.

“The administration has already committed to extending the life of the B61 gravity bomb for decades to come and to developing a new nuclear-capable, stealthy long range bomber,” the letter said. “These capabilities, combined with existing nuclear and conventional options, make the new cruise missile redundant.”

The senators also criticized the cost of the program, saying it could draw away funding that could be better put to use in higher priority programs. According to the letter, the Air Force plans to buy at least 1,000 to 1,100 new nuclear cruise missiles, which are projected to cost between $20 billion to $30 billion.

The Air Force Association on Monday issued its own letter to the chairmen and ranking members on the congressional armed services committees, imploring lawmakers to fully fund the program.

“We do not agree with the recent suggestion that cancellation of the current U.S. plan to buy 1,000 nuclear-capable air-launched cruise missiles will inspire other countries to stand down their nuclear forces and lead to a global ban, and there are no signs the long-established military requirement for a nuclear-capable standoff cruise missile has diminished,” said AFA President Larry Spencer and Vice President Mark Barrett. “Instead, maintaining a strong LRSO capability provides the most non-proliferation incentive by convincing allied countries they do not need to develop their own nuclear weapons.”

The United States needs to be mindful of the uncertainty associated with using a dual-capable cruise missile, but the deterrent value of such weapons outweigh the risks, retired Air Force Gen. Robert Kehler, the former commander of U.S. Strategic Forces Command, told a House panel last week (Defense Daily, Dec. 10).

 “We’ve only ever operationally used them—thank heaven, in conventional modes—and we’ve been able to work the ambiguity issue. When a cruise missile lifts off a surface ship, or when it drops out of a B-52 bomb bay, or if it comes out of an SSGN [nuclear-capable submarine], no one believes that we’ve just launched a nuclear weapon,” he said during a House Armed Services Committee strategic forces subcommittee hearing.