“Impeachment,” wrote British historian and ambassador Viscount James Bryce, “is the heaviest piece of artillery in the congressional arsenal, but because it is so heavy it is unfit for ordinary use. It is like a hundred-ton gun which needs complex machinery to bring it into position, an enormous charge of powder to fire it, and a large mark to aim at.”

The House has rolled out the hundred-ton gun. An extraordinary measure, befitting extraordinary circumstances. President Donald Trump has long shown manifest unfitness for office, but the Ukraine scandal stands apart. Last week we learned of Trump’s Mafioso-like conditioning of foreign military aid on help criminally investigating a political rival. We will continue learning more as details trickle out, especially if congressman Adam Schiff succeeds in persuading the still-anonymous whistleblower to testify. But it would be a mistake to imagine that Schiff’s success in getting that testimony is vital: We already know enough to say that Trump has betrayed his country and endangered national security.

But that knowledge only begins the inquiry. Impeachment is a fearsome power, and our Constitution demands careful inquiry before its deployment. The goal of impeachment, after all, is not merely shortening an abusive leader’s time in office. The goal is safeguarding American democracy. An impeachment proceeding, even when successful, rips asunder the national fabric and leaves lasting scars on our already-fragile public psyche. Those costs are real and serious.

Yet there remain circumstances in which impeachment is absolutely necessary despite its costs. Impeachment is fraught with peril, but so too is non-impeachment: The long-term damage to our nation from tolerating the intolerable counts, too. We must take seriously both sets of costs.

Given these complexities, responsible discussions of impeachment must consider three questions. First, has the president engaged in conduct that warrants his removal under the Constitution? Second, is the effort to remove him likely to make a positive impact—or will impeachment be a mere quixotic quest? And third, would impeachment be worth the resulting rupturing of our national fabric?

In other words: Is impeachment permissible? Is it reasonably likely to succeed? And is it worth it? Let us review the evidence.

High Crimes and Misdemeanors

Americans have never reduced to a simple formula what it means to commit “high Crimes and Misdemeanors.” A working definition captures two general elements. First, impeachable offenses represent betrayal of office. And second, those offenses pose such a serious risk of harm that they require preventive action—in other words, they suggest that the president endangers the nation. Such offenses may involve a pattern of closely related abuses, rather than a single deed. But the ultimate inquiry is whether the president has so betrayed his office and poses such a continuing threat that leaving him in power could imperil our constitutional democracy.

This president has done just that.

Begin with the White House readout of Trump’s phone conversation with Ukrainian President Volodymyr Zelensky. That readout, even in its presumably sanitized form, reveals a multitude of impeachable offenses. On that call, Trump abused the foreign policy and military powers entrusted to the president by Article II to serve his own political interests—and perhaps those of his sometime-benefactor, Russian President Vladimir Putin, whose tanks have penetrated Ukrainian territory and would be opposed by the military aid Trump was unilaterally withholding—rather than the interests of the American people.

The goal of impeachment, after all, is not merely shortening an abusive leader’s time in office.

The resultant cover-up, too, is staggering. We have learned that the effort to protect the president ensnared numerous senior White House officials, including the lawyers representing not the president personally but the presidential office. Indeed, the whistleblower complaint alleges that the cover-up was part of a pattern of systematically overclassifying politically embarrassing information to protect the president. Such conduct betrays the institution of the presidency and poses a clear and present danger to our national security. It does so by compromising the integrity of our system for classifying intelligence, thereby undermining the confidence of our key allies in how the secrets they share with us will be handled. And it conceals the ongoing danger posed to our most sensitive secrets by the seemingly reckless way our commander in chief deploys those secrets for personal advantage or political leverage.

The only real question now is whether an impeachment inquiry should focus narrowly on the Ukraine events or broadly examine the mosaic of offenses Trump has committed while in office and in the course of acquiring the presidency. Both approaches have merit. On one hand, Ukraine-gate offers a clear reckoning: Its disgraceful character is undeniable (though many have tried, sometimes by pretending not to know what our president said to Ukraine’s). On the other, it represents just one of the myriad abuses Trump has perpetrated during his time in office, and highlighting his repeated national betrayals might emphasize the urgency of his removal.

In any event, one fact is clear: We already know enough to impeach. Trump is so demagogic, corrupt, and self-aggrandizing that he normalizes conduct that ought to have been deemed impeachable from the start. We must interrupt his attempts at normalization. What we have now is enough. The transcript is enough. The cover-up is enough. Enough is enough.

Impeachment Politics

The president has committed impeachable offenses. But that sad reality does not end the conversation. The House retains the discretion to decline impeachment, even where the underlying offenses warrant it. Often the House will have valid reasons for staying its hand—political, legal, or otherwise. Not here. Trump’s manifest betrayals of his oath require immediate action.

One common argument from the left against impeachment is that the Senate is all but certain not to convict, so the whole process will only strengthen Trump. Not so. Formal impeachment by the House, whatever further evidence comes out, might put useful pressure on senators to stand up and be counted rather than be seen by the nation as burying the case alive. The House might also decline to refer the matter to the Senate for trial. The House is empowered to reach a verdict on its own after conducting a full and fair hearing without a referral to the Senate, as I have argued elsewhere.

Even still, there is no doubt that Trump will seek to exploit a senatorial acquittal on the 2020 campaign trail. But that is all but irrelevant, because, whatever happens, this president will claim vindication and witch hunt, his familiar tropes. Indeed, he is already crying “treason” to brand those who are investigating his conduct with the most lethal term our legal and political lexicon has to offer. We cannot make decisions based on fear of what fables Trump might spin.

Our National Trauma

The primary arguments against impeachment—articulated by liberals like Bruce Ackerman, moderates like Frank Bruni, and reactionaries like John Yoo—do not deny the gravity of the president’s violations. Rather, they argue that impeachment is not worth the national costs of enraging the incumbent president’s supporters, fanning the flames of the white-hot anger that drove many of them into his camp in the first place, and leaving even some who might be prepared to vote against Trump in 2020 with the sense that a group composed almost entirely of Democrats is illegitimately undoing the results of an election with which they never came to terms. We should weigh those costs carefully as we consider how to proceed.

But those concerns cannot outweigh the imminent concern of a lawless presidency. Yes, impeachment would be traumatic. But what is the alternative? Acquiescing to lawlessness out of fear? And declining to impeach would be traumatic as well.

Impeachment is, in any event, unlikely to be as nationally dangerous as the alternative. The nation is so divided that whatever added division the impeachment and trial process entail would not qualitatively worsen the situation—at least on balance, if one weighs impeachment against the bitterness, despair, and helplessness that failure to impeach would leave in its wake. If we are honestly ready to say we would impeach even if we were sympathetic to the president’s policies and not opposed to him on purely personal grounds unrelated to the survival of our republic, if we would vote to impeach even if the shoe were on the other foot, then we should not hesitate out of sheer nervousness. Caution is appropriate. Cowardice is not.

Yes, impeachment would be perilous. But not nearly as perilous as the alternative. Inaction is no longer an option. It’s time for the hundred-ton gun.