(WASHINGTON) — The United States is on a collision course with its NATO ally Turkey, pushing ahead with arming Syrian Kurds after deciding the immediate objective of defeating Islamic State militants outweighs the potential damage to a partnership vital to U.S. interests in the volatile Middle East.

The Turks are fiercely opposed to the U.S. plans, seeing the Kurdish fighters as terrorists. And when Turkish President Recep Tayyip Erdogan visits the White House this week, the most he and President Donald Trump may be able to do is agree to disagree, and move on.

“The Turks see this as a crisis in the relationship,” said Jonathan Schanzer at the Washington-based Foundation for Defense of Democracies.

The challenge is hardly new. Long before Trump took office, U.S. presidents have grappled with the fragility of partnering with Turkey’s government and the Kurds to carry out a Middle East agenda.

Past administrations have sought a delicate balance. Too exuberant in its support for the Kurds, and the U.S. risks pushing ally Turkey toward U.S. geopolitical rivals like Russia or emboldening the Kurds to try to create an independent state — a scenario that would destabilize multiple countries in the region. Too little cooperation with the Kurds risks squandering a battlefield ally with proven effectiveness against extremist threats and who has staunchly supported Washington.

Trump has made his priorities clear.

His administration is arming Syrian Kurdish fighters as part of an effort to recapture the Syrian city of Raqqa, the Islamic State group’s self-declared capital. Coupled with the U.S.-backed fight in the Iraqi city of Mosul, Raqqa is seen as a key step toward liberating the remaining territory the militants hold.

Turkey has been pressuring the U.S. to drop support for the Kurdish militants in Syria for years and doesn’t want them spearheading the Raqqa effort. Turkey considers the Syrian Kurdish group, known as the YPG, a terrorist group because of its ties to the outlawed Kurdish Workers’ Party inside Turkey. The United States, the European Union and Turkey all agree the PKK is a terrorist…