The Massachusetts Senator was quick to respond to President Donald Trump’s Twitter announcement Wednesday that, after consulting with “generals and military experts,” the government “will not accept or allow Transgender individuals to serve in any capacity in the U.S. Military.”

Warren’s take on Trump’s transgender military ban was that it wasn’t a military one at all, but rather it was an ideological one. In a series of tweets, she wrote: “By attacking thousands of troops, @realDonaldTrump makes clear that he cares more about extreme ideology than military readiness.”

The only thing – only thing – that matters when it comes to allowing military personnel to serve is whether or not they can handle the job.

— Elizabeth Warren (@SenWarren) July 26, 2017

By attacking thousands of troops, @realDonaldTrump makes clear that he cares more about extreme ideology than military readiness.

— Elizabeth Warren (@SenWarren) July 26, 2017

.@realDonaldTrump can pretend this is a military decision, but it isn't. Banning troops on gender identity is shameful & makes us less safe.

— Elizabeth Warren (@SenWarren) July 26, 2017

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Warren’s words echo a statement made by former Defense Secretary Ash Carter, who ended the transgender military ban for service members just last year.

“To choose service members on other grounds than military qualifications is social policy and has no place in our military,” he said in a public statement at the time. “There are already transgender individuals who are serving capably and honorably. This action would also send the wrong signal to a younger generation thinking about military service.”

Trump’s rationale for the decision was the costliness of health care for transgender military members. “Our military must be focused on decisive and overwhelming victory and cannot be burdened with the tremendous medical costs and disruption that transgender in the military would entail,” he wrote Wednesday.

A 2016 RAND study commissioned by the Defense Department found that the medical costs of trans service members represented an “exceedingly small portion of active-component health care expenditures.” According to the study—which analyzed health insurance data on gender transition-related expenditures—extending medical care to transgender service members would increase costs by $2.4 million to $8.4 million a year. That comes out to be between one-tenth and one-twentieth of a percent.