Global Oil Prices See Record Monthly Decline Amid Iran Peace Hopes

As May concluded, the global Brent oil benchmark recorded its largest one-month decline in six years, falling nearly 20% throughout the month [2]. This shift in the energy market has provided some relief to consumers, with the average price of unleaded gasoline in the United States falling 17 cents per gallon from its recent peak [2].

Key takeaways

• Brent crude prices dropped nearly 20% in May, marking the largest monthly decline since 2020 [2].
• U.S. crude oil prices fell approximately 17% in May, the largest monthly decline since April 2025 [2].
• Despite recent drops, both Brent and U.S. crude prices remain up by more than 50% since the start of the year [2].
• Energy industry leaders warn that low commercial inventories could lead to future price spikes exceeding $150 per barrel [2].

The impact of diplomatic messaging

The sharp decline in oil prices was primarily driven by consistent messaging from the White House, where President Donald Trump and administration officials have suggested that the United States and Iran are nearing a peace agreement [2]. Throughout May, the President claimed in at least six social media posts that progress toward a deal was being made, and he has stated more than 20 times over the past three months that the war was nearing an end [2]. While oil prices fell in response to these signals, U.S. officials noted that a final agreement has not yet been signed [2].

Despite the market optimism, the situation regarding the Strait of Hormuz remains uncertain. The waterway, which accounted for over 20% of the world’s energy supply before the conflict, has seen almost no vessel traffic in recent months [2]. Industry experts, including Chevron CEO Mike Wirth, have cautioned that even if a deal is reached, clearing mines and managing the backlog of 2,000 ships will take weeks or months [2]. Furthermore, Iran’s proposal to charge tolls for safe passage remains a significant point of contention that the U.S. has labeled a deal-breaker [2].

Why it matters

While consumers are currently seeing lower prices at the pump, energy executives warn that the market remains volatile. Exxon Mobil senior vice president Neil Chapman noted that commercial inventories of crude and refined products have been depleted to compensate for the lack of transit through the Strait of Hormuz [2]. Industry leaders suggest that if these inventories continue to shrink, oil prices could surge significantly, potentially reaching $150 per barrel [2]. As the market watches for a formal resolution to the conflict, analysts at ING warn that investors may be overly optimistic, as it remains unclear whether the current diplomatic efforts will lead to a lasting peace or merely a prolonged stalemate [2].