In his confirmation hearings to become an Associate Justice on the United States Supreme Court, Judge Brett Kavanaugh was asked how he felt about President Donald Trump’s desire to authorize torture that is “worse than waterboarding.” Kavanaugh’s response? “I don’t think I can comment.” Responding to a clarifying question on whether–with the benefit of hindsight and the Senate’s report on the CIA detention and interrogation program–he feels that the use of waterboarding and other brutal techniques was torture, Kavanaugh couldn’t bring himself to denounce this shameful and immoral practice. Rather than emphatically acknowledging that waterboarding is clearly a violation of both domestic and international law, he went on merely to state the obvious: that judges should follow the law. He did not mention that his colleagues in the White House he served in manipulated the law he now swears to uphold to provide a veneer of legality for waterboarding and other unthinkable, unlawful conduct. Whether Kavanaugh, if confirmed to the Court, would follow the law and determine that waterboarding is unlawful, remains unknown.

Kavanaugh has not always been so reluctant to talk about torture. In his 2006 confirmation hearings for a federal judgeship, when asked about the brutal and humiliating torture and detainee abuse of the Abu Ghraib prison scandal, Kavanaugh reaffirmed President George W. Bush’s disingenuous statement that the United States does not torture or condone torture. But now that he’s been nominated for a life-time appointment to our country’s highest court, Kavanaugh cannot bring himself to acknowledge the illegality of the torture techniques that the current Commander-in-Chief has promised to reinstate. And so it goes on dozens of issues on which judge Kavanaugh refuses to make simple commitments to uphold and apply clearly established law. If the Senate confirms Kavanaugh to the Supreme Court, I fear it could mean that important and settled legal precedents are chipped away or overturned entirely, to the detriment of the rule of law and core American values.

In June 2008, the Supreme Court issued a landmark decision in Boumediene v. Bush, ruling that prisoners at Guatanamo Bay have the constitutional right to habeas corpus review. While acknowledging the preeminent role of the “political branches” in counterterrorism, it concluded that “security subsists, too, in fidelity to freedom’s first principles, chief among them being freedom from arbitrary and unlawful restraint and the personal liberty that is secured by adherence to the separation of powers.”

The author of that 5-4 decision was Justice Anthony Kennedy. Such a stance was nothing new for Kennedy, who had voted with the majority in other decisions—in Rasul v. Bush (2004), Hamdi v. Rumsfeld (2004), and Hamdan v. Rumsfeld (2006)—that protected constitutional freedoms in the counterterrorism context. Since 9-11, the Supreme Court has served as a crucial, if inconsistent, check on the executive branch as presidents seek more power in the name of fighting terrorism.

That may change if the Senate confirms Brett Kavanaugh, who throughout his career has shown an excessive deference to presidential power and a corresponding disregard for constitutional rights. By replacing a thoughtful and moderate justice with an arch-conservative, there’s no telling what impact it may have on abortion to gay rights to money in politics and beyond.

The one area I can speak to is national security, where I worry that Kavanaugh’s role on the Court could be harmful to both our security and our rights. Although legal issues pertaining to counterterrorism aren’t front page news of late, they remain urgent and unsettled. Indeed, Kavanaugh has been nominated by a president who has pledged to reinstate torture and send more detainees to Guantanamo.

As the former Judge Advocate General of the United States Navy, I saw first-hand how our laws orient our fighting force to find success on the battlefield. Our military is best served by clear rules governed by constitutional and law of war principles, and that reflect essential American values. When laws are contorted to justify torture, indefinite detention, or substandard military trials, the long-term sustainability of the military itself is corroded.

A review of Kavanaugh’s decisions reveals a judge who envisions a dangerously restricted role for the courts, and a future in which Guantanamo exists as a near-permanent feature of counterterrorism policy. As a member of the U.S. Court of Appeals for the District of Columbia Circuit, for example, he supported a bare minimum standard of proof to justify detention, which has led to the denial of virtually all habeas petitions brought by Guantanamo detainees in recent years. In 2009, he signed onto an opinion that rejected claims against private contractors who had tortured people at Abu Ghraib.

Judge Kavanaugh’s rejection of judicial review is especially glaring in light of the manifest failures of Guantanamo’s military commissions. These legally dubious, problem-plagued proceedings have produced only a handful of convictions, and several of these have been overturned on appeal. Nonetheless, Kavanaugh voted to uphold their use for the prosecution of domestic crimes, as opposed to war crimes. In a 2014 dissent, he approved of Congress’s decision to prohibit his court from reviewing military commission cases, except in the case of post-conviction appeals.

The other major weakness in Kavanaugh’s jurisprudence is his insistence on the near-irrelevance of international law. In 2010, ruling on Bihani v. Obama, he rejected a Guantanamo prisoner’s claim that his detention violated international law on grounds that international law, unless explicitly stated, is “not part of domestic U.S. law.”

The Constitution, however, says treaties ratified by the United States “shall be the Supreme Law of the Land” and elsewhere references “the law of nations.” That’s why the Supreme Court has often cited international law in its rulings, including those upholding the due process rights of Guantanamo detainees.

The U.N Convention Against Torture, which the United States has ratified, is a key component of the prohibition on torture, which also includes federal laws such as the 2015 McCain-Feinstein amendment. Does Judge Kavanaugh agree with “torture memo” authors John Yoo and Robert Delahunty that “customary international law cannot bind the executive branch under the Constitution”? The very limited documents that have been released on Kavanaugh’s time in the White House demonstrate that he misled the Senate in his 2006 confirmation hearing when he stated that he was not involved with any detainee policy issues. We now know he was, and that includes the time period in which the torture program and other controversial detainee policies were developed and implemented. What role, if any, did he play? What, if anything, did he say about it?

Senators should press for answers to these questions, which are far from academic. At the outset of President Trump’s term, opposition from Congress forced him to scrap an executive order that would have reauthorized torture and brought back CIA prisons. But another major terrorist attack could alter the political dynamics, not only on torture but also Guantanamo and other national security issues.

Even without greater transparency from Judge Kavanaugh, there is plenty in his record to concern those of us who believe that the threat of terrorism is no reason to abrogate rights, and that, in fact, rights-respecting policies are the best way to combat terrorism. Given President Trump’s open desire to do away with limits on his power, Judge Kavanaugh is a good choice for him. And, unfortunately, a bad choice for the country.