Kanter has been a thorn in the side of the Turkish regime for some time now, largely because of his outspoken criticism of Turkey President Recep Tayyip Erdogan. Kanter has also been a vocal supporter of Turkish opposition leader Fethullah Gulen, who lives in the United States and is in exile for allegedly plotting the overthrow of strongman Erdogan last year. Apparently, Turkey had enough of Kanter's activism:
According to AFP, a Turkish judge on Friday issued an arrest warrant for Kanter. The 25-year-old is accused of having “membership” in “an armed terrorist organization.”
Though Kanter is currently in the United States, and the US has an extradition agreement with Turkey, he has little fear of being extradited because American policy generally disfavors the extradition of political dissidents.
The arrest warrant comes on the heels of another recent Turkish provocation: the revocation of Kanter's passport while he was en route from Romania to the United States. Had Kanter been working for the Thunder on an O-1 or P-1 visa (which is the norm for most foreign basketball players in the NBA), he would have been denied entry to the US and would have faced possible jail time in Turkey for his political activities.
Fortunately for Kanter, he possesses a green card, which allows for reentry to the United States even without a passport. As a result, he was able to return to the USA despite Turkey's cancellation of his passport. Turkey's attempt to thwart his travel plans failed.
From the US Customs and Border Protection (CBP) website:
Lawful Permanent Residents of the U.S. must present a Permanent Resident Card ("Green Card", Form I-551), a Reentry Permit (if gone for more than 1 year), or a Returning Resident Visa (if gone for 2 years or more) to reenter the United States.U.S. LPRs do not need a passport to enter the United States as per 8 CFR 211.1(a), however, they may need a passport to enter another country. Please contact the embassy of the foreign country you will be traveling to for their requirements.
This is one (of few) areas where CBP regulations are actually more lax than one might expect.
Since he was born in Switzerland, Kanter can presumably procure a passport from Switzerland, and continue, unabated, to be a thorn in the side of the Erdogan regime.