A proposal to the Senate’s annual defense policy bill that would have established a U.S. Cyber Force as the country’s latest military branch was narrowly defeated this week, according to multiple congressional sources.

An amendment by Sen. Kirsten Gillibrand (D-NY) to the chamber’s fiscal 2027 national defense authorization bill that would have created the digital-focused service was defeated 14-13 when the Senate Armed Services Committee took up the nearly $1.2 trillion legislation behind closed doors this week. 

Nine Democrats and four Republicans voted in favor of the amendment, these sources, who spoke on the condition of anonymity, said.

The main argument against the New York Democrat’s proposition was that policymakers should wait for the results of a study on feasibility of creating a Cyber Force by the National Academy of Sciences, Engineering, and Medicine (NASEM) that was included in a previous defense roadmap before moving forward.

That examination, which Gillibrand also championed, is expected to conclude later this year.

The close committee vote is a surprise considering that Congress has not studied, in depth, the possibility of a Cyber Force. It is also the latest clear-cut example of bipartisan frustration on Capitol Hill over the chronic failure by the existing military services to provide U.S. Cyber Command with personnel who are ready to battle foreign adversaries online like China and Russia.

“It's been an item that we've been reviewing,” Sen. Mike Rounds (R-SD), who chairs the Armed Services cyber subcommittee, told Recorded Future News.

“We're not sure this is the right time,” he added, citing the NASEM review. “Part of it is because of the changing nature of how you actually address security issues surrounding cyber. [Artificial intelligence] is a major part of the discussion.”

Earlier this month, an independent commission published a report that laid out in detail how the U.S. should proceed in one day establishing a seventh military branch. The new uniformed branch would cost up to $11 billion to create and feature an estimated total of 33,000 troops, including 20,000 active duty members, the panel found.

Gillibrand’s amendment, which has not been released publicly, was widely believed to mirror the commission’s recommendations, including nesting the Cyber Force within the Army, similar to how Space Force is underneath the Air Force.

“We remain optimistic about Cyber Force and the senator will continue to push for its creation,” a Gillibrand spokesperson said in a statement.

A new ‘dual-hat’

While the Cyber Force wasn’t included in the sprawling bill, it does feature a sweeping reorganization of the Defense Department’s cyber offices.

The bill would create a new Under Secretary of Defense for Cyber, Information, and Networks that is dual-hatted as the Pentagon’s Chief Information Officer and the principal cyber advisor to the Secretary of Defense.

The provision, which would take effect in two years, is an attempt by lawmakers to get ahead of ongoing tensions between the CIO and the assistant secretary of defense for cyber policy. 

At the core has been a difference of opinion over what constitutes cyber operations, according to multiple military, civilian and congressional sources with direct knowledge of the disagreement.

The assistant secretary’s office has claimed that such efforts belong to it statutorily, while the CIO equates the activities to cybersecurity as a whole, making it her organization’s responsibility. 

“In a world of Mythos and various other highly capable artificial intelligence models in the cyber and networking domain, there's really an importance of aligning, of creating the unity of policy and compliance mechanisms in protecting our networks,” a congressional official told reporters on Thursday.

“We realized that there were some frictions and gaps between the activities of the CIO and the principal cyber advisor,” the official added. The new office would “minimize some of the inherent friction that has come over time, as these two roles have ultimately matured.”

Rounds, a longtime leader on digital issues, said the envisioned Senate-confirmed post would “literally bring cyber back up to a higher level than what it is today and eliminate any friction between two offices: one design to identify offensive and defensive operations, and CIO, which is the platforms that this lives on.”