US moves to ramp up pressure on Iran at UN as Tehran warns of 'recalibrated' military posture

Washington is moving to increase diplomatic pressure on Tehran over its nuclear program as Iran threatens a new Persian Gulf exclusion zone and warns it has “fundamentally recalibrated” its posture toward U.S. warships and bases.

The United States has submitted a draft resolution to the UN Security Council that would demand Iran cease all uranium enrichment above 60% and grant the IAEA expanded access to undeclared sites. The draft, circulated by US Ambassador Linda Thomas‑Greenfield on April 26, is co‑sponsored by France and the United Kingdom and invokes the snapback mechanism of the 2015 JCPOA to reimpose UN sanctions if Iran does not comply within 30 days. According to the latest IAEA report, Iran’s stockpile of uranium enriched to 20% stands at approximately 2,800 kilograms, up from 1,900 kilograms a year ago, while its 60% enriched material totals about 150 kilograms.

If Iran follows through on its threat to create a 12‑nautical‑mile exclusion zone in the Strait of Hormuz, global oil supplies could drop by roughly 21 million barrels per day. Analysts estimate that a sustained 10% reduction in Hormuz flow could push Brent crude up by $5 per barrel, which typically adds about $0.12 to the price of a gallon of gasoline in the United States. For a driver who travels 12,000 miles a year in a vehicle averaging 25 mpg, that increase would raise annual fuel costs by roughly $60.

The current push mirrors the 2018 US withdrawal from the JCPOA, after which Iran began gradually expanding its enrichment activities in response to renewed sanctions. Since then, Tehran has periodically announced maritime security measures in the Gulf, such as the 2021 declaration of a temporary naval exercise zone that coincided with a spike in regional insurance premiums for tankers. Insiders note that behind the scenes, US officials have been coordinating with Gulf allies to pre‑position additional naval escorts, a move that has not been publicly disclosed but is seen as a deterrent to any actual closure attempt.

The Security Council is scheduled to vote on the US‑drafted resolution on May 10, 2025. Analysts say a positive vote would trigger a 30‑day compliance window for Iran, after which the snapback sanctions could be reimposed unless Tehran addresses the enrichment concerns. Surprisingly, despite the heightened rhetoric, Iran’s oil exports to China rose by 18% in April, suggesting that alternative buyers may blunt any immediate supply shock from a Hormuz disruption.