The brief flirtation with sub-$100 oil is over.

Brent crude surged 4% to $105.50 per barrel on Monday, May 12, 2026, after President Trump publicly rejected Iran’s latest peace proposal, describing Tehran’s response as “totally unacceptable” in a social media post on Sunday evening. West Texas Intermediate jumped 4.4% to $99.80, pushing the U.S. benchmark back toward the $100 level it had briefly fallen below last week amid optimism over a potential 14-point diplomatic framework.

The price reversal erased virtually all of the gains that peace optimism had delivered to energy markets over the past five trading sessions. It also reintroduced a risk that traders had been tentatively pricing out: the possibility that the Strait of Hormuz could remain disrupted well into the second half of 2026, with no diplomatic off-ramp in sight.

What Happened

The sequence of events that led to Monday’s oil spike began on Sunday, May 11, when the Trump administration received Iran’s formal response to the latest U.S. negotiating framework. The two sides had been exchanging proposals through Pakistani intermediaries since late April, and markets rallied sharply last week on reports that a deal was close.

Iran’s counter-proposal, according to multiple reports, included three core demands: an immediate end to hostilities, Iranian management of the Strait of Hormuz, and a complete end to the U.S. blockade on Iranian exports. The first condition was expected. The second and third were not — at least not in the form Tehran presented them.

Trump responded on Sunday evening via social media, calling the proposal “totally unacceptable” and signaling that the United States was prepared to maintain its current military posture in the region. The post did not close the door on future negotiations entirely, but its tone was sharply dismissive.

Israeli Prime Minister Benjamin Netanyahu reinforced the hawkish framing hours later, warning that the Iran conflict is “not over” and that Israel reserves the right to act independently to protect its security interests in the region. The combination of Trump’s rejection and Netanyahu’s comments created the conditions for a risk-on move in energy markets the moment Asian trading desks opened on Monday morning.

The U.S.-Iran conflict, which began on February 28, 2026, has already produced a series of escalation-de-escalation cycles. The UAE intercepted Iranian missiles on May 4, followed by a brief period of renewed diplomacy that pushed Brent below $100 for the first time in over two months. Monday’s reversal marks the third time since March that oil prices have spiked above $105 on geopolitical developments.

Why Oil Prices Spiked

The 4% move in Brent is significant, but the underlying mechanics are more concerning than the headline number suggests.

Strait of Hormuz risk repricing. Roughly one-fifth of the world’s oil shipments transit the Strait of Hormuz. When diplomatic talks appeared to be progressing, traders began gradually removing the geopolitical risk premium that had been embedded in crude prices since late February. Trump’s rejection forced an immediate reassessment. Iran retains significant control over the timing of any Strait reopening, and Sunday’s developments demonstrated that Tehran is using that leverage to extract concessions well beyond what Washington is willing to accept.

Short covering. Speculative short positions in crude oil futures had built up over the past week as traders bet on a diplomatic resolution. When Trump’s post landed, those positions were squeezed. The resulting short-covering amplified the price move beyond what fundamental supply-demand dynamics alone would have produced.

Supply constraints remain real. Iranian oil exports have been severely curtailed since the conflict began. OPEC+ production discipline has been tighter than expected. Russian output has been flat. And U.S. shale production, while robust, has not been growing fast enough to offset the combined effect of these constraints. The International Energy Agency’s latest supply-demand balance shows global inventories drawing at a rate of approximately 1.2 million barrels per day — a pace that leaves minimal buffer against further disruptions.

No alternative diplomatic pathway. The collapse of the latest negotiating round leaves no clear mechanism for restarting talks. The Trump-Xi summit scheduled for May 14-15 in Beijing could provide a backchannel opportunity, as China has significant influence over Iranian decision-making as Tehran’s largest oil customer. But that summit’s primary focus is trade, not Middle East security, and expectations for a breakthrough on Iran are low.

Impact on Inflation and Consumers

The timing of Monday’s oil spike is particularly unfortunate for American consumers and for the Federal Reserve.

The Bureau of Labor Statistics releases the April CPI report on Monday morning, and the consensus forecast already pointed to an acceleration in headline inflation to 3.7% year over year — up from 3.3% in March. The March CPI data showed the energy index surging 10.9% in a single month, with gasoline prices jumping 21.2%. Those numbers reflected oil prices in the $88-$92 range. With Brent now trading above $105, the May CPI data — due in mid-June — could be materially worse.

The pass-through from crude oil to gasoline prices is neither instant nor linear, but the direction is clear. National average gasoline prices, which had dipped toward $3.90 per gallon during last week’s peace-optimism rally, are likely to reverse course and push back toward the $4.20-$4.50 range within the next two to three weeks if crude remains above $100. In California and parts of the Northeast, $5.00 gasoline is already a reality.

For lower-income households, this is not an abstraction. Gasoline accounts for a disproportionate share of spending for workers who commute by car and cannot easily absorb a 20% increase in fuel costs. The University of Michigan’s consumer sentiment survey already fell to 48.2 in its preliminary May reading — the lowest since June 2022 — with year-ahead inflation expectations surging to 4.7%. Monday’s oil move is unlikely to improve that picture.

The broader inflation transmission mechanism extends beyond the gas pump. Diesel prices affect shipping costs, which feed into food prices, industrial goods, and retail products. Jet fuel prices affect airfares. Natural gas prices, which correlate loosely with oil over medium-term horizons, affect electricity costs and home heating. When oil sustains a move above $100, the inflationary impulse radiates across the entire consumer price basket, not just the energy line item.

What Analysts Are Saying

Wall Street’s energy desks moved quickly on Monday to revise their near-term price targets.

Citi analysts said in a morning note that prices could rise further from current levels, with risks “tilted to the upside” as long as the Strait of Hormuz remains partially restricted. Their base case assumes Brent averaging $102-$108 per barrel through June, with a tail-risk scenario of $120+ if the conflict escalates further or if Iranian-backed proxies target oil infrastructure in the Gulf.

Goldman Sachs, which had lowered its Brent forecast to $95 last week on deal optimism, acknowledged that the “risk-reward has shifted back to the upside” following Trump’s rejection. The bank noted that the speed of the reversal — from diplomatic optimism to outright rejection in fewer than five days — highlights the binary nature of geopolitical risk in current oil markets.

JPMorgan’s commodities team warned that the market is “underpricing the duration risk” of the conflict. In their view, the core problem is not whether the U.S. and Iran will eventually reach a deal, but how long the process will take. Every additional month of elevated oil prices compounds the inflationary damage, narrows the Fed’s policy options, and erodes consumer purchasing power.

Several analysts pointed to a structural asymmetry in the current situation: Iran retains significant control over the timing of any Strait of Hormuz reopening, while the U.S. has limited ability to force a resolution without either accepting Tehran’s terms or escalating the military conflict. This dynamic gives Iran negotiating leverage that is unusual for a country under active economic sanctions and military pressure.

What to Watch Next

The next 72 hours will determine whether Monday’s spike is the start of another sustained leg higher in oil prices or a one-day reaction that fades as markets digest the implications.

April CPI data (May 12). The inflation report landing on the same day as the oil spike creates a compound narrative problem for policymakers. If the number prints at or above the 3.7% consensus, the combination of accelerating inflation and rising oil prices will put immediate pressure on the Federal Reserve — and on incoming Fed Chair Kevin Warsh, whose Senate confirmation is expected this week. Warsh’s first FOMC meeting on June 16-17 is already shaping up to be one of the most consequential in recent memory.

Trump-Xi summit (May 14-15). The Beijing meeting remains the most plausible near-term venue for a diplomatic reset on Iran. China purchases roughly 1.5 million barrels per day of Iranian crude and has been Iran’s most important economic lifeline throughout the conflict. If Xi Jinping signals a willingness to pressure Tehran toward a more realistic negotiating position, markets could stabilize. If the summit focuses exclusively on trade and avoids the Iran question, the geopolitical risk premium in oil will persist.

Iranian counter-moves. Tehran’s response to Trump’s rejection will matter more than the rejection itself. If Iran signals a willingness to revise its demands, the door to negotiations remains open. If Iran retaliates by further restricting Strait of Hormuz transit or by resuming military provocations, the $105 price could quickly become a floor rather than a ceiling.

OPEC+ posture. Saudi Arabia and the UAE have spare production capacity that could, in theory, offset some of the supply disruption. But both countries have been reluctant to increase output during the conflict, partly for revenue reasons and partly to avoid antagonizing Iran. Any signal from Riyadh that it is willing to open the taps would provide a price offset — but that signal has not come, and market participants are not expecting it.

Fed communication. Several Federal Reserve officials are scheduled to speak this week. Their comments on the inflation outlook, the oil price shock, and the path of monetary policy will be scrutinized for any hints about whether the June meeting could produce a hawkish surprise. As the S&P 500’s six-week winning streak demonstrates, equity markets have been priced for a relatively benign scenario. A sustained oil shock threatens that assumption.

Bottom Line

Monday’s oil price surge is a concrete reminder that the Iran conflict remains the single most important variable in the global economic outlook. The diplomatic progress that markets celebrated last week has been replaced by a deadlock. Iran wants concessions the U.S. is unwilling to grant. The U.S. wants a resolution Iran is unwilling to accept on Washington’s terms.

The result is an energy market stuck above $100, an inflation trajectory that is accelerating rather than decelerating, and a Federal Reserve that is running out of room to wait. For consumers, the consequence is straightforward: gasoline prices are going back up, and there is no near-term catalyst to bring them down.

The conflict that began on February 28 is now 73 days old. The longer it lasts, the deeper the inflationary damage embeds itself into the U.S. economy. Monday’s price action suggests that resolution is further away than it appeared just five days ago.