• Marco Rubio asserts that charging tolls on international waterways violates international law.
  • Iran's efforts to formalize tolls on the Strait of Hormuz face unified opposition from the U.S. and allies.
  • Potential tolls could disrupt global energy markets, raising shipping costs and insurance premiums.

A Clear Legal Stance

Senator Marco Rubio has firmly stated that no country is permitted to charge tolls or fees for passage through an international waterway, emphasizing that this principle is established under existing international law. His comments come amid reports that Iran is seeking to institutionalize tolls on the Strait of Hormuz, a critical chokepoint for global oil and LNG shipments. "International waterways must remain toll-free and open to all navigators," Rubio said, according to people familiar with the matter. The U.S. has signaled a unified position against any such monetization, framing it as a breach of freedom of navigation.

Iran's Push and Regional Dynamics

Iran has reportedly been in discussions with Oman to formalize a toll mechanism for vessels transiting the Strait of Hormuz. If implemented, this would mark a significant shift in control over one of the world's most vital maritime routes. The move has drawn sharp reactions from major powers, including the United States and China, with diplomatic efforts underway to preserve open transit. The dispute centers on whether Iran can unilaterally charge fees without multilateral agreement, a question that touches on core principles of international maritime law.

Market Implications and Risks

The potential for tolls or restrictions on Hormuz has already raised concerns among shippers and insurers. The strait carries a substantial share of global oil and LNG, and any disruption could lead to higher shipping costs and altered routing decisions. Insurers may reassess risk premia for vessels transiting the region, potentially driving up costs for crude and refined product shipments. Energy markets are closely watching the developments, with volatility expected if toll proposals gain traction.

Diplomatic and Legal Context

The debate underscores broader tensions over freedom of navigation and the ability of states to monetize strategic waterways. U.S. and allied officials have framed tolls as illegitimate and destabilizing, with some reports suggesting joint diplomatic statements opposing the move. The outcome will depend on how major powers coordinate their responses and whether Iran's proposals gain international backing.

Correction: An earlier version of this article misstated the timing of Rubio's comments; they were made earlier this week.