On Feb. 9, the Senate confirmed Kathleen Hicks as the deputy secretary of defense after her testimony before the Senate Armed Services Committee on Feb. 2. Hicks may be the Pentagon’s most influential player on nuclear weapons issues during the Biden administration, and her confirmation hearings shed new light on the administration’s policies in this area.

She offered a stronger endorsement of nuclear modernization than her boss, Secretary of Defense Lloyd Austin. Her testimony raised new questions, however, about the Biden administration’s nuclear posture, including on a possible “no first use,” or NFU, doctrine. The Senate should seek answers to these important questions in future confirmation hearings with Biden national security officials.

Hicks’ views on nuclear modernization may be even more important than Austin’s. As a former board director for Raytheon, Austin is required by law to recuse himself from Raytheon-related matters for one year. Under questioning from Sen. Elizabeth Warren, however, Austin committed to recusing himself for the duration of his tenure as secretary of defense.

Furthermore, in response to written questions from SASC, Hicks confirmed that “[Austin] expressly indicated his intent to avoid both conflicts of interest and the appearance of any such conflict. This broadly scoped recusal will almost certainly prohibit Secretary Austin’s participation in programmatic discussions on such matters as the Ground Based Strategic Deterrent, Long Range Stand Off weapon, and other timely missile defense issues.”

As a result, Hicks will likely be the Pentagon’s primary decision-maker at the Pentagon on matters related to nuclear modernization.

During his confirmation hearing, Secretary Austin endorsed the nuclear triad of bombers, submarines and intercontinental ballistic missiles, but he was less committal on nuclear modernization. The current systems of the U.S. nuclear triad were built at the end of the Cold War and need to be updated. The Obama administration put in place a plan to modernize the triad, and those plans were continued by President Donald Trump. But Austin claimed that before continuing these modernization plans, he would first need to “get under the hood” and consult with U.S. Strategic Command.

Hicks, in contrast, was less ambiguous. When asked by Sen. Deb Fischer whether she supported modernizing the triad, Hicks said, “Yes,” adding that “the triad has been the bedrock of our deterrent.”

Hicks told Sen. Tom Cotton that nuclear modernization decisions should be driven “by strategy,” not cost, and emphasized her commitment “to a modernized, qualitatively effective deterrent.”

While Hicks’ support for nuclear modernization is encouraging for supporters of the U.S. nuclear deterrence mission, she did leave herself flexibility on the particulars of modernization. She noted that it was “difficult to assess exactly the timeline, margin and technical feasibility” of modernization.

This hesitation is concerning because delaying modernization would mean relying for longer on aging nuclear systems that have extended past their intended service lives.

Senators also questioned Hicks on the potential adoption of an NFU policy, which would alter U.S. declaratory nuclear policy to state that the United States would only use nuclear weapons in response to an enemy nuclear attack. The Obama-Biden administration considered such a shift, but ultimately decided correctly that this would only invite aggression from China and Russia, and worry allies who depend on U.S. nuclear deterrence to meet their security needs.

Under questioning from Sen. Cotton, Hicks argued that she personally thought an NFU policy would be a bad idea, but that “those will be decisions made by the president.”

In sum, Hicks’ confirmation hearing revealed sound judgement on nuclear weapons policy. Let us hope that her views on nuclear modernization and NFU carry the day in the Biden administration’s internal policy debates. When other defense officials testify before Congress in the days and weeks ahead, senators should press them to support modernization and reject NFU. Maintaining a strong U.S. nuclear deterrent demands no less.

Matthew Kroenig is deputy director of the Scowcroft Center for Strategy and Security at the Atlantic Council. He has worked on nuclear weapons issues for the Defense Department and is the author of “The Logic of American Nuclear Strategy.” Mark Massa is assistant director of the Forward Defense initiative at the Scowcroft Center for Strategy and Security. Raphael Piliero is a young global professional with Forward Defense.