Sen. Lindsey Graham on Monday championed the Senate’s willingness to publicly rebuke the Saudi Arabian government despite the White House’s unwillingness to do the same, slamming the Gulf monarchy and calling out Secretary of State Mike Pompeo by name for accusing senators of grandstanding on the issue.

Graham (R-S.C.), a fierce ally of President Donald Trump, voted last week in favor of advancing a resolution that would end U.S. support for Saudi Arabia’s involvement in the civil war in Yemen, despite Pompeo’s warning against the measure. Graham, writing in The Wall Street Journal, said “it is important for Congress to signal that there is no excuse for recent Saudi behavior.”

“It is wrong to suggest that maintaining U.S. alliances consists of mutually exclusive choices between power and principles,” Graham wrote, citing the recent murder of dissident journalist Jamal Khashoggi inside a Saudi consulate, arguing that “extrajudicial killing of a journalist in a diplomatic facility is nothing if not uncivilized.”

Beyond the war in Yemen, in which the Saudi military has been accused of killing civilians, Graham criticized Saudi Arabia’s blockade of Qatar last year and its attempts to remove Lebanon’s prime minister, noting that despite those maneuvers, Saudi Crown Prince Mohammed bin Salman has been hailed as a stabilizing force in the kingdom.

“I’d hate to see what destabilizing behavior looks like,” Graham wrote.

Although the Trump administration has taken some steps to sanction some within the Saudi government involved in Khashoggi’s murder, the president, secretary of State and secretary of Defense have all said there is no definitive proof that the Saudi crown prince ordered Khashoggi killed. Multiple media outlets have reported that U.S. intelligence agencies have “high confidence” that the crown prince ordered the journalist’s murder.

Graham, in his op-ed, agreed with the president that Saudi Arabia is an invaluable ally in the region, but he called Salman “a wrecking ball to U.S.-Saudi relations” and wrote that the U.S. “has the leverage to demand better” from the regime.

“Demanding better from allies isn’t downgrading the relationship; it’s a sign that Americans take our principles seriously and won’t be taken advantage of by anyone, friend or foe,” he said.

Responding to Pompeo’s insistence that Congress breaking with the administration over Yemen would undermine the possibility for peaceful resolution there, Graham retorted in his op-ed that Congress is “a coequal branch of government exercising leadership to safeguard the country’s long-term interests, values and reputation.”

“After all, someone’s got to do it,” he wrote.