Cohen’s message is significant not only because of what he said, but because of the journey he’s been on in coming to terms with Trump. Last March, when a Donald Trump presidency was but a fever dream for the candidate’s detractors, Cohen and 121 other Republican national-security experts condemned the likely GOP nominee. They denounced Trump’s anti-Muslim rhetoric, his rough treatment of Mexico and other U.S. allies, his advocacy of torture and trade wars, and his praise for authoritarian leaders like Vladimir Putin. They characterized him as erratic, dishonest, and hostile to American civil liberties. “[A]s committed and loyal Republicans,” they wrote in an open letter, “[w]e commit ourselves to working energetically to prevent the election of someone so utterly unfitted to the office.”

“Hillary is the lesser evil, by a large margin,” Cohen, who helped organize the letter, said at the time. Trump’s victory would be “an unmitigated disaster for American foreign policy."

Hillary Clinton is now hiking in Chappaqua, while the Unmitigated Disaster, in Cohen’s view, is headed to the White House. So how should “Never Trumpers” like Cohen, and Republicans who have been quieter about their qualms about Trump, respond? Should they lend their experience, if not their enthusiastic support, to a president who has never held public office and could use the guidance? Is the principled stand to defend their views and values from within the government, or from without? What are the ethics of working for a president who you not only fundamentally disagree with, but view as a possible threat to the country and its principles?

Ross Douthat of The New York Times has argued that, unless Trump’s presidency descends into “naked authoritarianism,” ambivalent Republicans have a “moral responsibility” to serve in Trump’s administration and to check the president’s “worst impulses,” particularly in the relatively free-wheeling, high-stakes realm of foreign policy. David Luban, a law professor at Georgetown University, has made the opposite case, arguing that serving in a Trump administration could mean acquiescing to Trump’s authoritarian impulses and targeting of political opponents. “Don’t tell yourself you can tame the beast, because the beast will tame you,” he writes.

Two days after the election, Cohen offered his own anguished answer. He would not be serving President Trump—“They will have no use for me, or, to be fair, I for them”—but he urged like-minded Republicans to consider taking positions in the new administration:

It seems to me that if they are sure that they would say yes out of a sense of duty rather than mere careerism; if they are realistic in understanding that in this enterprise they will be the horse, not the jockey; if they accept that they will enter an administration likely to be torn by infighting and bureaucratic skullduggery, they should say yes. Yes, with two conditions, however: that they keep a signed but undated letter of resignation in their desk office (as I did when I was in government), and that they not recant a word of what they have said thus far. Public service means making accommodations, but everyone needs to understand that there is a point where crossing a line, even an arbitrary line, means, as Sir Thomas More says in A Man for All Seasons, letting go without hope of ever finding yourself again. It goes without saying that friends in military, diplomatic, or intelligence service—the career people who keep our country strong and safe—should continue to do their jobs. If anything, having professionals serve who remember that their oath is to support and defend the Constitution—and not to truckle to an individual or his clique—will be more important than ever.

Cohen’s about-face on Tuesday doesn’t just hint at coming schisms among Republicans on foreign policy (Cohen is associated with an interventionist wing of the Republican Party, embodied by George W. Bush, that Trump has long criticized). It also suggests that Cohen and Douthat and Luban might have been asking the wrong question. They were debating whether qualified Republicans who didn’t support Trump should serve in his administration. But the more pertinent question may be whether qualified Republicans who didn’t support Trump will be asked to serve in his administration, particularly in its upper ranks.