WASHINGTON — As the clock ticks down on the final term of US President Barack Obama, who is believed to be reviewing a potential disarmament agenda for his last months in office, there has been a flurry of activity on Capitol Hill to try to influence the internal debate.

Lawmakers both pro and con for nuclear modernization have fired off dueling letters—the latest a July 20 letter to Obama from five key House Democrats who want to scale back standing nuclear modernization plans.

In addition to potential budget cuts, the White House is mulling several other disarmament initiatives. The Washington Post reported earlier this month that they included a five-year extension of the New START agreement, United Nations approval of the unratified Comprehensive Test Ban Treaty, and a public pledge that the United States would never use nuclear weapons unless another nation used them first—as well as the cancellation of the Long-Range Stand Off (LRSO) weapon program to replace aging cruise missiles.

Following the report came the letter signed by House Armed Services Chairman Ranking Member Adam Smith, D-Wash., and others, which backed the no-first-use policy declaration and eliminating the launch-on-warning nuclear posture as "steps that could avoid an unintentional or hasty start to unprecedented and catastrophic nuclear devastation."

Nuclear modernization plans have become unaffordable and untenable in the face of statutory budget caps, the letter warns.

"At a time when the United States is facing an extremely complex threat environment and Congress shows no indication that it will eliminate its budget caps, this plan risks squandering hundreds of billions of dollars on certain weapons programs that will likely be either delayed or cancelled, and it will plunder much-needed funds for conventional military forces in the process," the letter reads.

Five ranking members signed on: Reps. Smith; Chris Van Hollen, D-Md., of the Budget Committee; Marcy Kaptur, D-Ohio, of the Appropriations Energy and Water Development Subcommittee; Loretta Sanchez, D-Calif., of the Armed Services Tactical Air and Land Subcommittee; Jackie Speier, D-Calif., of the Armed Services Oversight and Investigations Subcommittee.

× Transitioning out of the service? Sign up for the Rebootcamp Newsletter to receive helpful information on education, employment and entrepreneurship. Thanks for signing up. By giving us your email, you are opting in to the Rebootcamp Newsletter.

On the opposite side of the aisle, HASC Chair Mac Thornberry, R-Texas, told reporters the nuclear deterrent is the foundation of US national security, and downplayed its expense in the context of the larger defense budget. Anything that calls the commitment to nuclear deterrence into question, he said, "results in a more dangerous world."

"Some of these calls for further cuts are irresponsible in my opinion," Thornberry said.

Competing visions are also evident within the platforms of the Democratic and Republican parties, whose conventions to nominate their presidential candidates—Hillary Clinton and Donald Trump respectively — are this month.

The GOP platform invokes Cold War-president President Ronald Reagan, with a peace-through-strength style approach and a robust "Reagan-era force." It advocates a multi-layered missile defense system, nuclear modernization, an end to the mutually assured destruction doctrine and to rebuild relationships with allies, "who understand that as long as the U.S. nuclear arsenal is their shield, they do not need to engage in nuclear proliferation."

"We should abandon arms control treaties that benefit our adversaries without improving our national security," the platform reads.

"To this end, we will work to reduce excessive spending on nuclear weapons-related programs that are projected to cost $1 trillion over the next 30 years," a draft of the platform reads.

Still, the partisan split on nuclear modernization is not a clean one. A bipartisan group of 14 senators signed a July 8 letter spearheaded by Sen. John Hoeven, R-N.D., that called on Defense Secretary Ash Carter to reaffirm the Pentagon's commitment to modernize the nation's nuclear triad.

They are Sens. Steve Daines, R-Mont.; Jon Tester, D-Mont.; Orrin Hatch, R-Utah; Joe Donnelly, D-Ind.; Heidi Heitkamp, D-N.D.; Marco Rubio, R-Fla.; Mark Warner, D-Va.; David Vitter, R-La.;, Martin Heinrich, D-N.M.; John Barrasso, R-Wyo.; Deb Fischer, R-Neb.; the Senate Armed Services Committee's ranking member Jack Reed, D-R.I., and Clinton's running mate, Tim Kaine, D-Va.

Key military officials back nuclear modernization. The House Armed Services Strategic Forces Subcommittee hosted military officials in charge of the nuclear arsenal July 14, where Adm. Cecil Haney, head of U.S. Strategic Command, said the president's 2017 budget request, contained "no margin to absorb" cuts.

Rand described the ALCM as "a ten-year missile in its thirtieth year" which will be increasingly vulnerable to enemy air defenses, while the nascent stand-off weapon will be tougher for an enemy to target.

"You don't want to get into the eye of the tiger if you can avoid it," Rand said.

A group of 10 Democratic senators signed a separate letter to Obama July 20 urging him to cancel LRSO development. It was signed by Sens. Ed Markey and Elizabeth Warren of Massachusetts, Dianne Feinstein and Barbara Boxer of California, Al Franken of Minnesota, Jeff Merkley of Oregon, Sherrod Brown of Ohio, Patrick Leahy of Vermont, Ron Wyden of Oregon, and Bernie Sanders, the Vermont senator who recently ended his campaign for the presidency.

Senate Armed Services Chair John McCain, R-Ariz., and Senate Foreign Relations Chair Bob Corker, R-Tenn., signed a June 17 letter urging Obama to stick with nuclear modernization plans, arguing he is bound by longstanding commitments he made to Congress.