🟡 Iran says it will target US naval vessels, UAE leaves OPEC, GPT-5.5 similar to Mythos on cyber tasks || Global Risks Weekly Roundup #18/2026

Executive summary

Geopolitics: Iran unveiled a fresh peace proposal, but Trump was not satisfied with it and says that Iran has not paid a big enough price for the war to end yet. The US said it would guide stranded vessels through the Strait of Hormuz, but Iran warned it could attack US naval vessels in response.

• Will Congress put any constraints on the war in Iran by June 1, 2026, using the War Powers Act? Our forecasters think there’s a 6% (5% to 7%) chance.

• Will there be a new conflict in Africa that kills over 100k people before May 1, 2027? Our forecasters think there’s a 17% (15% to 30%) chance.

Technology and AI: OpenAI’s GPT-5.5 was found to have a similar level of performance to Anthropic’s Mythos model on the UK AISI’s suite of cyber tasks. Unlike Mythos, it has been publicly deployed.

• Will OpenAI de-deploy GPT-5.5, making it unavailable to the general public, before 2027 because of its use in cyberattacks? Our forecasters believe there’s a 7% (5% to 8%) chance.

Economy: Brent crude oil prices reached a new war-related high, as did gas prices in the US. Outgoing Fed Chair Jerome Powell says he will stay on the institution’s Board of Governors. The UAE withdrew from the OPEC cartel.

• What will be the highest Brent crude oil price in 2026? Our forecasters’ 50th percentile estimates average $137 ($126 to $175), for Trading Economics’ hourly average.

Geopolitics

Middle East

Iran submitted a fresh, 14-point peace proposal to the US via Pakistan, but Trump was “not satisfied” with it. He later said that Iran has “not paid a big enough price” for the war to end yet.

The US said it would begin guiding vessels that have been stranded in the Gulf region through the Strait of Hormuz. Iran, in turn, warned that any US navy vessels participating in such an operation could be attacked and claimed to have hit an American warship in the Strait, which the US denied.

Israel sent a version of its “Iron Beam” laser system to the UAE to help intercept Iranian missiles and drones. This is significant because it is an explicit defense cooperation between Israel and an Arab state. It is also significant because the system is very new, and Israel is unlikely to have enough of it to cover its own territory.

The Americas

Mexico’s President Claudia Sheinbaum opposes extraditing a Mexican state governor unless sufficient evidence is provided for why he was indicted in the US on drug trafficking charges. The governor in question, Ruben Rocha, has temporarily stepped down.

Trump again suggested that the US could try to bring about regime change in Cuba once the Iran War has concluded: “On the way back from Iran, we’ll have one of our big - maybe the USS Abraham Lincoln aircraft carrier - the biggest in the world, we’ll have that come in, stop about 100 yards offshore, and they’ll say, ‘Thank you very much. We give up’.”

The United States

The US passed the 60-day mark since the start of the war with Iran. According to the War Powers Act, the President must terminate hostilities within 60 days unless Congress declares war. On Friday, Trump suggested that the War Powers Act is unconstitutional. Secretary of Defense Hegseth had earlier said that the “60-day clock was effectively paused when Trump announced a ceasefire with Iran in April.”

Our forecasters think there’s a 6% (5% to 7%) chance that Congress will use the War Powers Act to put any constraints on the war in Iran before June 2026 and overall do not expect Republicans to meaningfully push back against the executive branch.

The US Supreme Court’s ruling on Louisiana v Callais gives some advantage to Republican redistricting and weakens the Voting Rights Act of 1965 by making majority-minority districts subject to much greater scrutiny. Polymarket perhaps moved +5% on Republican control in the Senate after the midterms after the ruling, though it’s hard to establish causality.

Europe

Following criticism from German Chancellor Frederich Merz that Iran was “humiliating” the US and that he didn’t see an exit strategy, Trump ordered the withdrawal of 5,000 troops from Germany. The US currently has 35,000 to 38,000 troops stationed there. Trump said on Saturday that he would “go a lot further” with additional cuts.

Rheinmetall’s CEO claims that Germany’s capacity to produce conventional ammunition now exceeds that of the US.

Africa

Tuareg and jihadist rebels in Mali took control of a key military outpost in the north of the country, in a setback for the country’s Russia-backed ruling junta.

Our forecasters think there’s a 17% chance (15% to 30%) that a new conflict will break out in Africa that results in the death of at least 100,000 people before May 1, 2027. A recent instance of such a conflict is the 2020-2022 Tigray war.

Technology and artificial intelligence

The UK’s AI Security Institute (AISI) found that OpenAI’s newly released model, GPT-5.5, reaches a similar level of performance to Anthropic’s Mythos Preview on its suite of cyber evaluations.

Unlike Mythos, GPT-5.5 has been publicly deployed. Our forecasters think there’s a 7% probability (5% to 8%) that OpenAI will have to “de-deploy” GPT-5.5, making it unavailable to the general public, before 2027.

One forecaster writes:

It does seem plausible to me that Mythos-level hacking capabilities do give you the ability to collapse society, via financial institutions, but also probably through other pathways.

There are three pieces here that I’m decently confident in:

1. Mythos is a super duper hacker

2. If Mythos was generally available today we probably would be cooked

3. GPT-5.5 is basically as good as Mythos at hacking (and it is publicly deployed)

I really feel like I should say 1+1+1=3, therefore we’re cooked. But I hesitate. My generator for hesitation is like, maybe I’ve missed something, and especially the thought “Surely OpenAI wouldn’t do something this insane”, but I think this is a terrible heuristic. And just generally the feeling that bad things don’t happen very often.

But there have been previous times when forecasters have looked at the decisions people in positions of power are making and noted that 1+1+1=3 (we’re cooked), e.g., with Covid. I remember it well. But I feel pretty confused and uneasy about this.

The opposite case might be that Mythos practical cybersecurity prowess has been greatly exaggerated, or that society will end up being fairly resilient to cyberattacks as a result of having good enough practices, bad actors not having enough compute, and the threshold to causing harm to civilization as a whole being fairly high.

The White House opposed Anthropic’s plan to expand access to Mythos to an additional 70 companies; this would allow more actors to patch software but also introduce security risks and reduce the company’s ability to serve the model to the USG. Germany’s central bank has urged the EU to seek access to Mythos, reporting that banks are in “difficult waters” without access to the model.

The US’s Cybersecurity and Infrastructure Security Agency has proposed to cut government bug-patching deadlines from 3 weeks to 3 days.

The Pentagon reached deals with seven tech companies, including Nvidia, OpenAI, Google, Microsoft and Amazon, to use their AI-related services in its classified networks. One forecaster wonders whether the decision to use the technologies of multiple companies may reflect a desire not to concentrate too much power in the hands of one company or model.

Ubuntu, a popular operating system, suffered a cyberattack, with the “Islamic Cyber Resistance in Iraq” claiming responsibility.

US Senator Bernie Sanders is continuing to speak out on AI extinction risk. He held a panel with American and Chinese AI scientists, Max Tegmark, David Krueger, Xue Lan and Zeng Yi, to discuss the risks posed by AI and the need for international cooperation.

EU countries and lawmakers failed to reach a deal on weakened EU AI Act rules.

Ukraine’s defense ministry said that 96% of Russian casualties in March were caused by drones.

The New York Times reports that some bioscientists are getting increasingly worried by biorisks arising from AI.

Economy

The United Arab Emirates (UAE) announced its withdrawal from OPEC and the wider OPEC+ framework on Tuesday. The UAE and Saudi Arabia were the main OPEC partners with significant excess capacity. Although previously more coordinated, the UAE has been pursuing its own foreign policy strategy, for instance, supporting its own proxies in Yemen, Sudan and Somalia. Although the UAE has one third the population of Saudi Arabia, its economy is one half as large, and its oil diversification strategy has been more successful than Saudi Arabia’s Vision 2030 attempts. But the UAE’s banking system has been in trouble as a result of the war with Iran, and it recently asked the US for a currency swap line, meaning it can access dollars directly without selling its treasuries and stocks.

Western economies are increasingly going to face consequences of the Strait of Hormuz closure. Demand destruction is expected as oil stores are drawn down and consumption must come into line with an approximately 10% reduction in oil shipments from the Persian Gulf.

The price of Brent crude oil reached a new war-related high of $120.65 on an hourly basis. Our forecasters’ 50th percentile estimates for where the Brent crude oil price will peak in 2026 average $137 ($126 to $175). This will be resolved according to Trading Economics’ hourly average.

US petrol and diesel prices reached a new war-related high this week. US airlines are struggling with high jet-fuel prices; budget airline Spirit Airlines went out of business. The University of Michigan’s US Consumer Sentiment Index dropped to a historic low in April 2026.

Outgoing Federal Reserve Chair Jerome Powell said that he would stay on the institution’s Board of Governors for the time being, and “will not leave the board” until an investigation into the renovation of the central bank’s headquarters “is well and truly over with transparency and finality”. In doing so, he will deprive Trump of the chance to appoint an additional member of the board who would follow his wishes on interest rate decisions. This also deprives Trump of a majority on the board, of which 3 out of 7 are currently Trump appointees, not including Powell. Trump’s nominee to be the next chair will be replacing Stephen Miran, who is well aligned with Trump on monetary policy, so the balance is not likely to shift in the near term.

Trump said he would raise tariffs on EU trucks and cars to 25% from 15%, accusing the bloc of failing to comply with a US-EU deal.

Biorisk

Three people on a cruise ship have died, and one has been confirmed to have died of hantavirus. Others are sick. The ship left Argentina in March. This is significant because there is some evidence that one species of hantavirus found in Argentina and Chile, the Andes Virus, is capable of limited human-to-human transmission. Cruise ships provide close quarters that are ideal for disease spread; any outbreak will be very limited.

Nature and climate

With a strong El Niño expected to start in the coming months, statistics from past years suggest that we can expect to see half as many major hurricanes and about 40% fewer hurricanes overall in the coming Atlantic hurricane season.