President Donald Trump is trying to force Ukrainian President Volodymyr Zelensky into a peace agreement with Russia by browbeating Zelensky rhetorically and withholding military aid as leverage. This playbook has stunned Washington, but it shouldn’t be entirely unfamiliar: For much of 2024, progressive Democrats pleaded with the Biden administration to deploy a similar approach against Israeli Prime Minister Benjamin Netanyahu to stop the war with Hamas.

No, President Joe Biden never called Netanyahu a “dictator,” as Trump did Zelensky, but Democrats such as then-Senate Majority Leader Charles E. Schumer (New York) did seek Netanyahu’s wartime removal from office (in a speech Biden praised). No, Biden never made bullying demands of Netanyahu in front of the cameras, but he did push Israel hard to accept a deal with Hamas that fell well short of fulfilling Israel’s military objectives. No, Biden’s White House never announced a weapons embargo against Israel, but it did bottle up arms deliveries to express displeasure with Israel’s insistence on pursuing Hamas in the Gazan city of Rafah.

In other words, Biden didn’t apply the same level of pressure against Israel to end the conflict on his terms as Trump is applying against Ukraine. But Biden’s perceived tentativeness dismayed progressives in Congress, the media and the Democratic base to no end. They said Israel was taking U.S. support for granted and disrespecting the president. With his punitiveness and pungency, Trump is behaving toward Zelensky the way progressives wish Biden would have behaved toward Netanyahu.

This comparison infuriates liberals, who see pressure on Israel as well-meaning and Trump’s efforts to coerce Ukraine as nefarious. But that’s precisely the point: Foreign policy is often a projection of domestic political ideals. Which of the world’s wars are vital to U.S. interests, and which are mere “territorial disputes” or “ethnic rivalries”? Which allies are righteous sentinels of American values, and which are ungrateful dependents? A country that can’t agree on its fundamental ideals will struggle to answer those questions in a consistent way.

The consistency in Trump’s approach — a tight leash for Ukraine, freer rein for Israel — is that the president tends to tilt toward the stronger party. Russia is stronger than Ukraine, and Israel is stronger than its ring of Iran-backed enemies.

It takes less U.S. effort to forge a peace that is acceptable to the stronger party. Meanwhile, the conventional Democratic approach to these two conflicts — hold back Israel while declaring a willingness to back Ukraine “as long as it takes” — requires more diplomatic exertion by Washington. It aligns with the liberal instinct to stand with the “underdog,” but it has also proved politically unsuccessful.

The Trump administration seems to see less of a U.S. interest in Europe’s defense partly for ideological reasons. Instead of regarding the European Union as a model of humane liberal democracy, many conservative populists see a cautionary political tale in the continent’s geopolitical decline, bureaucratic government and progressive excesses. (This was Vice President JD Vance’s message in Munich last month.) Meanwhile, Democratic skepticism of Israel has clearly been influenced by the projection of American identity politics onto the Israeli-Palestinian conflict, with Israel playing the role of oppressor.

But no matter a president’s ideological outlook, Washington’s ability to force peace on an unwilling ally in an existential war depends in part on that ally’s domestic politics. The Biden administration’s entreaties and ultimatums to Israel always felt doomed to fail because they underestimated the degree to which Israel’s political system was united around the government’s aggressive stance against Hamas. Netanyahu at one point said that even if the United States cut off weapons, Israelis would “fight with our fingernails,” and the opposition did not contradict him.

Trump might well face a similar challenge trying to impose an unsatisfying peace on Ukraine. Ukrainians won’t agree to a peace that looks like their country’s death warrant. On the other hand, progressives were convinced throughout the war with Hamas that if only Biden had used more of the United States’ leverage against Netanyahu, Israel might have had no choice but to obey his commands.

Trump’s hardball diplomacy will test the limits of Washington’s capacity to use brute force to control states that rely on U.S. backing to survive in dangerous neighborhoods. Keith Kellogg, Trump’s special envoy for the Russia-Ukraine war, said on Thursday that the pause on military aid to Ukraine is “like hitting a mule with a two-by-four across the nose. You got their attention.”

The contours of the peace settlement Trump has in mind if and when he forces Ukraine to the negotiating table remain elusive. But the relentless liberal pressure on Biden to go harder on Israel during the last year of his presidency refutes the notion that coercing an ally at war is itself somehow beyond the pale. What we are seeing is a fracturing political consensus about what American values are and at which of the world’s pressure points they are most at stake.

Jason Willick is a Washington Post columnist focusing on law, politics and foreign policy.