Sen. Elizabeth Warren (D-Mass.), a member of the Senate Armed Services Committee who brandished her arms-control and anti-nuclear bonafides throughout 2018, announced this week she might run for president in 2020.

Warren said she has formed an exploratory committee for a presidential bid, fulfilling long-circulating rumors that she would seek the Democratic Party’s nomination in the next general election.

Warren did not mention nuclear deterrence in a four-and-a-half minute video posted online Monday to announce her aspirations. However, the second-term senator has already crystallized her feelings about nuclear weapons in general, and the ongoing U.S. nuclear modernization program in particular.

In a late November speech at American University in Washington, Warren laid down three nuclear policy pillars: legally bar the U.S. from a nuclear first strike; build no new nuclear weapons, including the low-yield W76-2 warhead called for in the Trump administration’s 2018 Nuclear Posture Review and funded by Congress last year; and preserve hard caps on U.S. and Russian nuclear weapons by extending the bilateral New Strategic Arms Reduction Treaty into 2026.

These are essentially the opposite of the initiatives put in place by the Trump administration, which has pledged to sustain and augment the 30-year refurbishment of the nuclear deterrent the Obama administration started in 2016.

Warren threw down a few markers in the newly ended 115th Congress that support some of her positions.

In late November, Warren pressed William Bookless, nominated to be the No. 2 official at the National Nuclear Security Administration (NNSA), to admit he would “lean toward extending” New START past its 2021 expiration. The Trump administration has already moved to cancel one nuclear arms treaty with Russia and has kept itself open to abandoning New START.

Early that month, Warren co-sponsored a bill that would prohibit the United States from acquiring missiles that operate in the range prohibited by the 1987 Intermediate-Range Nuclear Forces Treaty — a U.S.-Russian pact from which the Trump administration plans to withdraw in February, unless Moscow ceases development and deployment of a missile that Washington says violates the Cold War accord.

In June, during the lopsided debate in a GOP-controlled government about whether to fund the W76-2, Warren co-sponsored a doomed amendment to the 2019 National Defense Authorization Act that would have prohibited the NNSA from building the warhead this year as planned. The W76-2 will be a modified version of the existing W76 warhead used aboard Trident II-D5 ballistic missiles carried by Ohio-class submarines.

The Massachusetts populist already had W76-2 in her sights in April, when she told senior military officials testifying before the Senate Armed Services strategic forces subcommittee that the NNSA might not be able to create W76-2 while also grappling with ongoing programs to: modernize the W84 warhead for use on a new cruise missile; homogenize four different versions of the venerable B61 gravity bomb; and complete an ongoing modernization of current W76 warheads. The nonprofit Federation of American Scientists estimates there are 1,500 W76 warheads to modernize.

Warren is slated to remain on the Senate Armed Services Committee in the 116th Congress that gaveled in Thursday. If her presidential bid evolves beyond the just-announced exploratory phase, she could be spending less time in committee fine-tuning her nuclear policy message and more time on the campaign trail; pundits predict a protracted competition amid a crowded field for the Democrats’ 2020 nomination.