President Donald Trump’s administration is seeking to designate the Muslim Brotherhood political movement a foreign terrorist organization ― a move that experts warn would greatly complicate American diplomacy in the Middle East, fuel extremism and lead to the persecution of Muslim groups in the U.S.

The New York Times reported Tuesday that national security adviser John Bolton and Secretary of State Mike Pompeo are pushing for the designation. White House press secretary Sarah Huckabee Sanders said in a statement that the “designation is working its way through the internal process.”

It’s an alarming development for foreign policy experts across the political spectrum who say the Muslim Brotherhood, a loose umbrella association with organizations in different countries, is nowhere near the top of the list in terms of threats to U.S. national security. The terror designation, they say, will destabilize U.S. relations with countries where the Brotherhood or its sympathizers hold influence. Those countries include Jordan, Morocco, Kuwait and Turkey ― important U.S. allies against real terrorism.

“The greatest damage might be in the realm of public diplomacy,” Nathan Brown and Michele Dunne of the Carnegie Middle East Center wrote in January 2017, when the Trump administration was last considering the designation. “Using a broad brush to paint all Muslim Brotherhood organizations as terrorists would be understood by many Muslims around the world as a declaration of war against non-violent political Islamists — and indeed against Islam itself.”

The designation would put the Muslim Brotherhood on a government list with dozens of other organizations and would make it illegal for anyone under U.S. jurisdiction to provide “material support or resources” to the group. It would also ban members from traveling to the U.S., and would make them “removable” from the country, according to the State Department.

The Muslim Brotherhood was founded in Egypt in 1928 to advocate for governments to be run according to Islamic laws and values. Its most influential figures renounced violence decades ago, and its Egyptian branch won elections after mass uprisings deposed President Hosni Mubarak during the Arab Spring in 2011. That branch and the global Brotherhood movement fell into disarray in 2013, after the Egyptian military ousted President Mohammed Morsi.

For years, anti-Muslim hate groups in the U.S. — many of them with deep ties to Bolton and Pompeo — have promoted conspiracy theories attempting to tie political opponents and prominent American Muslim organizations to the Muslim Brotherhood. Frank Gaffney, a former Pentagon official and head of the Center for Security Policy, an anti-Muslim think tank, has baselessly linked the Muslim Brotherhood to such figures as Hillary Clinton aide Huma Abedin and conservative activist Grover Norquist.

While these anti-Muslim groups and their advocacy for the terror designation were once relegated to the fringe of American politics, they have real influence in Trump’s White House.