What legal authority does Mahmoud Mamdani have to arrest Benjamin Netanyahu if any?

1. What Mamdani has said — a mayoral pledge framed around the ICC

Zohran Mamdani has publicly stated he would “honour” the ICC arrest warrant for Benjamin Netanyahu and would order the New York Police Department to arrest Netanyahu if he visited New York, presenting the move as an effort by a city to enforce international law where the federal government has not ^{[1] [2] [7]}. Mamdani framed the promise as acting “within the bounds of the law” while arguing cities must show leadership on moral and legal issues ^{[5] [1]}.

2. The central legal obstacle: the U.S. is not party to the ICC

A core constraint is that the United States has not joined the Rome Statute and does not recognize ICC jurisdiction on U.S. territory, meaning there is no domestic legal mechanism obligating U.S. police to execute ICC warrants; reporting and fact‑checks stress that the ICC “has no jurisdiction in the United States” and federal law complicates local enforcement of ICC warrants ^{[3] [1] [5]}.

3. Federal supremacy in foreign affairs and preemption arguments

Legal commentators and analysis stress that foreign relations and recognition or enforcement of international warrants are the exclusive domain of the federal government; courts have consistently upheld federal primacy in foreign affairs, and commentators argue municipal enforcement of ICC requests would conflict with that constitutional allocation ^{[4] [5] [6]}. Congressional Republicans even proposed legislation to preempt state or local officials from honoring ICC warrants without federal authorization, explicitly targeting proposals like Mamdani’s ^[8].

4. Diplomatic immunity and practical policing limits

Scholarship and reporting point to diplomatic and head‑of‑state immunities and the practical limits of the NYPD: even if local officers tried to detain a foreign leader, immunity doctrines and federal determinations about whether a visit is “official” could block arrest, and municipal police lack the authority to effect international extradition without federal agencies like the Department of Justice or U.S. Marshals ^{[4] [6]}.

5. Precedents, political friction, and enforcement reality

Multiple outlets call the pledge a “practical impossibility” or a political stunt because of precedent and intergovernmental friction: experts told The New York Times that state or city efforts to enforce international warrants would likely run afoul of federal law and policy, and that federal agencies could override or block municipal actions ^{[1] [9] [5]}. Analysts note past incidents where state or municipal defiance on federal matters prompted court intervention, underscoring how isolated local action is unlikely to succeed ^{[5] [4]}.

6. Two competing interpretations in public debate

Supporters of Mamdani portray his vow as a principled, symbolic attempt to hold powerful actors accountable and to pressure national authorities to act; his campaign emphasizes moral leadership and the significance of the ICC warrant ^{[7] [2]}. Critics — including legal experts, Republican lawmakers and some commentators — call the plan illegal, unconstitutional or unenforceable, arguing it risks diplomatic fallout and intrudes on federal prerogatives ^{[8] [9] [10]}.

7. What would actually be required to make an arrest and prosecution happen

Available reporting explains that an arrest tied to an international indictment would demand federal engagement: even if local police detained someone, federal authorities would need to take custody for any extradition to the ICC or international prosecution, and federal law and policy currently block or complicate that pathway given the U.S. stance on the ICC ^{[6] [4] [3]}. The Department of Justice and other federal actors are therefore pivotal; the DOJ declined comment in at least one report, highlighting the political sensitivity ^[6].

8. Bottom line and limitations of the record

The sources consistently conclude Mamdani lacks a clear, legally effective unilateral authority as mayor to arrest and extradite a sitting foreign leader on an ICC warrant while the U.S. remains outside the Court and federal supremacy governs foreign affairs ^{[3] [4] [1]}. Available sources do not mention any statutory mechanism through which a U.S. city mayor could unilaterally compel federal recognition of an ICC warrant or overcome diplomatic immunity in such a case; therefore, without federal cooperation the pledge is widely described in reporting as symbolic or impractical ^{[5] [8] [4]}.