A new proposed Senate bill aims to establish clear guardrails for the U.S. military’s use of artificial intelligence (AI), drawing a definitive line on one of the most consequential questions in modern warfare: who has the final say when lethal force is used?
On June 8, Senator Adam Schiff (D-Calif.) introduced the proposed Human Authority in Lethal Operations Act of 2026, or “HALO Act,” which would impose sweeping requirements on the Department of War (DoW) to ensure that autonomous and semi-autonomous weapon systems remain under meaningful human control.
The legislation would establish new design standards, testing requirements, oversight procedures, and legal safeguards for military systems that use artificial intelligence to identify, recommend, prioritize, or engage targets.
The bill aims to ensure that responsibility for battlefield decisions remains with human commanders, rather than shifting to algorithms. The legislation would require the Pentagon to designate accountable commanders for any engagement involving AI-enabled autonomous or semi-autonomous weapons and mandates that those commanders retain “ultimate discretion, judgment, and control over the use of force.”
“The past few months have shown us that there is an urgent need for commonsense guardrails to ensure the Defense Department’s use of AI is in line with Americans’ national security and privacy priorities,” Sen. Schiff said in a press release. “There are good reasons to use AI technology to advance our national security,” although he emphasized that, like with any tool, AI should not be allowed solely to guide human enterprises, “particularly when the risks of harm can be fatal.”
The proposal arrives amid growing concern among policymakers, military planners, and technology experts about the increasing role of artificial intelligence in combat operations.
Significantly, these concerns are no longer theoretical. As The Debrief previously reported, Israel’s reported use of the AI targeting system “Lavender” in Gaza triggered renewed debate over how much trust militaries should place in algorithmic target selection, particularly when civilian lives may be at risk.
Other recent examples have added to the concern, including studies showing that AI models can escalate dangerously in simulated war games, as well as the Pentagon’s continued push toward autonomous drones, AI-controlled aircraft, and robotic battlefield systems.
Even Pope Leo XIV recently weighed in on the issue in Magnifica Humanitas, his first encyclical, or formal papal teaching letter, warning that autonomous weapons could make war more feasible and less subject to human control, and arguing that lethal decisions must not be delegated to opaque or automated processes.
While the Pentagon has repeatedly stressed its commitment to responsible AI development, the HALO Act would codify many of those principles into law and create new statutory requirements governing how military AI systems are designed, tested, approved, and monitored.
Among the bill’s most significant provisions are requirements that autonomous weapon systems operate within predefined geographic areas, target sets, and timeframes. If a system cannot complete an engagement within those authorized parameters, it would be required to terminate the engagement until additional human operator and commander review is completed.
The legislation also calls for extensive record-keeping, cybersecurity protections, and continuous oversight to guard against unintended engagements and hostile manipulation.
The bill would also require senior Pentagon officials to conduct formal reviews before AI-enabled weapons enter development and again before they are fielded. Those reviews would assess legal compliance, operational safety, reliability, cybersecurity, and risks to civilians and protected infrastructure under the Law of Armed Conflict.
Beyond battlefield autonomy, the legislation targets several controversial uses of artificial intelligence in national security. It would prohibit covered Defense Department AI capabilities from inferring a person’s religion, race, political identity, sexual orientation, or emotional state. It would also restrict the purchase or receipt of Americans’ personal data from data brokers or other third-party sources when that data was obtained in a manner that would violate the bill’s rules.
Perhaps most notably, the proposed HALO Act explicitly forbids removing humans from decision-making processes involving presidential actions related to nuclear weapons.
“No covered artificial intelligence capability may be used with the intent, purpose, or outcome of… removing a human from the chain of decisionmaking for actions critical to informing and executing decisions by the President, including initiating or terminating nuclear weapons employment,” the proposed bill reads.
The measure also includes whistleblower protections for personnel working on military AI systems, mandates regular reporting to Congress, and requires the Pentagon to identify and remediate any fielded systems that fail to meet the law’s requirements.
Existing autonomous systems would undergo a comprehensive review, and any system found to be noncompliant could face retirement, modification, or suspension pending corrective action.
While the bill includes exemptions for certain defensive systems, cyber capabilities, mines, and other categories of military technology, its wider message is that as artificial intelligence becomes more deeply integrated into national defense, Congress wants humans, not machines, to remain responsible for high-stakes decisions.
The HALO Act is not the only effort underway on Capitol Hill to establish guardrails around military AI.
In March, Senator Elissa Slotkin (D-MI) introduced the AI Guardrails Act. Last week, Senator Kirsten Gillibrand (D-N.Y.) introduced separate legislation that would similarly prohibit the Pentagon from using artificial intelligence to launch nuclear weapons, conduct warrantless surveillance of Americans, or deploy fully autonomous weapons.
“Right now, the Pentagon is moving toward deploying incredibly powerful AI technology without commonsense guardrails in place, which could have catastrophic consequences that make all of us less safe,” Sen. Gillibrand said in a statement. “We must act now – not to stifle technological progress, but to establish clear rules of the road that keep humans in charge and keep AI’s use in warfare smart and safe.”
The competing proposals could set the stage for a broader congressional debate over the role of artificial intelligence in future military operations, particularly if lawmakers seek to incorporate them into the Fiscal Year 2027 National Defense Authorization Act (NDAA).
Before that can happen, however, the HALO Act and similar proposals must navigate the legislative process. The bills will first be considered by the relevant Senate committee, where lawmakers may hold hearings, debate their provisions, amend the text, or decline to advance them. If approved, it would then need to pass both the Senate and the House before being sent to the president for signature, either as a standalone measure or as part of a larger NDAA.
“My legislation would protect Americans from unlawful domestic surveillance, ensure that humans in the chain of command exercise responsibility for the use of any lethal technology, and maintain strong ethical protections in the deployment of autonomous and semi-autonomous weapons,” Sen. Schiff said in a statement.
Tim McMillan is a retired law enforcement executive, investigative reporter and co-founder of The Debrief. His writing typically focuses on defense, national security, the Intelligence Community and topics related to psychology. You can follow Tim on Twitter: @LtTimMcMillan. Tim can be reached by email: tim@thedebrief.org or through encrypted email: LtTimMcMillan@protonmail.com