On March 23, 2026, former Secretary of Defense Jim Mattis made an argument that cut against the prevailing momentum toward a ceasefire. Ending the war with Iran now, he told Politico, "would essentially cede control" of the Strait of Hormuz to Tehran. "We're in a tough spot," Mattis said. "But walking away hands them the keys to 20 percent of the world's oil."
Mattis was making a strategic point about the Iran war. He was also, whether he intended to or not, articulating the precise lesson that analysts believe China is extracting from the entire Hormuz crisis — and quietly applying to its long-term planning for Taiwan.
The lesson: if you control a maritime chokepoint, you can hold the global economy hostage. And the United States has now demonstrated, in real time, how difficult it is to take that control back.
Act 1: What the Hormuz Crisis Has Proven
The Strait of Hormuz — a 21-mile-wide channel between Iran and Oman — is the single most important maritime chokepoint for global energy. Approximately 20 percent of the world's oil and 17 percent of liquefied natural gas passes through it daily. Before February 28, those figures were largely theoretical. Since the Iran war began, they are lived economic reality.
Within hours of the US-Israeli strikes that killed Supreme Leader Khamenei on the night of February 28, the Islamic Revolutionary Guard Corps Navy transmitted warnings over VHF radio to vessels in the strait, stating that no ships would be permitted to pass, according to Wikipedia's documentation of the Strait of Hormuz Crisis 2026. The closure is not a formal legal blockade — Iran never filed one. But military and shipping industry sources confirm that vessels have stayed in port or turned back, and the practical effect is near-total disruption.
WTI crude oil topped $100/barrel on March 17. Oil was above $112/barrel when Trump announced his 5-day pause on further strikes on March 23. A 10 percent drop followed the announcement — Brent crude fell to $99.94 — but oil has since climbed back above $100 as Iran denied the ceasefire talks Trump described were ever taking place.
Euronews, in a March 18 analysis, described Iran's strategy as one of "gradual escalation and long war — testing US, Israeli and Gulf resolve." The Soufan Center, an independent intelligence-focused think tank, documented the operational difficulty the US is facing in trying to reopen the strait: presenting Iran with a broad coalition of states willing to protect shipping requires diplomatic buy-in that has not materialized at scale.
The point is not that the US is losing. The point is that reopening a closed chokepoint is enormously costly — economically, diplomatically, and militarily — even when the country holding it closed is vastly outgunned in conventional terms.
Act 2: China Is Taking Notes
Brandon J. Weichert, a national security analyst writing for 19FortyFive, published a piece on March 23 with a blunt assessment: China is watching the United States struggle to reopen the Strait of Hormuz, and it is "taking notes on how to blockade the Taiwan Strait and 90 percent of the world's semiconductors."
The parallel is structural. The Taiwan Strait — the 110-mile-wide channel between China and Taiwan — is to the global technology economy what the Strait of Hormuz is to the global energy economy. Taiwan Semiconductor Manufacturing Company, known as TSMC, manufactures approximately 90 percent of the world's most advanced chips, including those used in smartphones, AI servers, military hardware, and automotive systems. A sustained blockade of the Taiwan Strait — not even a military invasion, just a blockade — would have cascading effects on the global tech supply chain within weeks.
The BeHorizon think tank, in a March 20 analysis of the Hormuz crisis's geoeconomic implications, noted that the conflict is already creating secondary semiconductor shortages: certain chemicals used in chip etching and cleaning transit the Persian Gulf region, and their disruption is threatening production lines even in facilities nowhere near Iran. The document states that "Japan and Taiwan have reflexively aligned with the US" while China has positioned itself as a "responsible stakeholder" calling for de-escalation — a framing that serves Beijing's long-term narrative construction regardless of the outcome.
The playbook Beijing is studying: close a strait, absorb the military pressure, hold on. The economic damage to your adversary may be sufficient to force negotiation before your military position deteriorates. Iran is testing this theory in real time. China is observing the results.
Act 3: The Mattis Warning and What It Actually Means
Mattis's argument — that ending the war now cedes Hormuz — is more complex than it first appears. It is not simply an argument for continuing military operations. It is a recognition that the post-war status quo matters as much as the war itself.
If the US and Israel reach a ceasefire with Iran before establishing durable mechanisms for freedom of navigation through Hormuz — international escorts, legally binding agreements, new naval postures — then Iran retains the demonstrated ability and implicit right to close the strait again the next time it faces military or political pressure. The precedent of the closure itself is the danger, regardless of whether oil flows today.
The Hill's reporting on Mattis cited him saying the US is "in a tough spot" — acknowledging that neither full military escalation nor premature withdrawal is a clean option. His implicit recommendation: establish the terms of Hormuz's post-war status before agreeing to any ceasefire.
That framing has direct implications for the Taiwan question. If the US demonstrates — through this conflict — that maritime chokepoint blockades are diplomatically negotiable rather than militarily revoked, Beijing absorbs that signal. The cost of a Taiwan Strait blockade, in China's calculus, becomes lower if it believes Washington will eventually seek a deal rather than fight through.
Act 4: The Numbers Behind the Stakes
The scale differential between the two straits is significant and worth stating plainly.
Hormuz carries approximately 20 million barrels of oil per day and 17 percent of global LNG. Its closure has pushed WTI crude up approximately 54 percent since February 28, according to market data. The economic damage is substantial but unevenly distributed — the US is far less dependent on Hormuz oil than Europe or Asia.
A Taiwan Strait blockade would be categorically different in its economic impact. TSMC's most advanced chips — the 3nm and 5nm process nodes that power AI training systems, military electronics, and the latest generation of consumer devices — have no viable alternative source. Samsung produces some advanced chips in South Korea; Intel's domestic US fabs are years behind TSMC's leading processes. A 6-month Taiwan Strait blockade that successfully disrupted TSMC production would cascade through every sector that depends on advanced semiconductors — which is, in 2026, essentially every sector of the modern economy.
The BeHorizon analysis estimates that "broad price inflation across the technology sector" would result from even a partial semiconductor supply disruption, with "the availability of smart devices and industrial semiconductors contracting while their commercial value rises sharply." That is a polite way of describing what would be a civilization-scale economic event.
Act 5: What the US Can Still Do
The strategic response to this problem — preventing China from treating the Hormuz precedent as a Taiwan template — operates on several levels simultaneously.
First, how the Hormuz crisis ends matters enormously. A ceasefire that includes enforceable freedom of navigation guarantees through Hormuz — with multinational naval escorts, an IAEA-monitored verification regime, and clear consequences for renewed closure — sets a different precedent than a ceasefire that simply stops the shooting.
Second, semiconductor supply chain diversification, which was already underway before this crisis through the CHIPS Act and allied investment in Japan and Europe, has new urgency. Every TSMC facility built outside Taiwan is one fewer hostage to a future blockade.
Third, the diplomatic message to Beijing needs to be clear: the US response to a Taiwan blockade would not look like its response to Hormuz. Taiwan's strategic significance to the US economy — not just as a geopolitical ally but as the irreplaceable source of 90 percent of the world's advanced chips — makes the calculus different.
Whether that message is being sent, and whether Beijing believes it, are separate questions.
The Record
Former Defense Secretary Jim Mattis warned on March 23 that ending the Iran war now would cede control of the Strait of Hormuz to Tehran permanently. The Hormuz crisis has driven oil up 54 percent since February 28 and forced the United States into a costly, politically complex effort to reopen a 21-mile chokepoint held closed by a country it has already militarily devastated.
China is observing. Beijing is reportedly assessing a similar economic blockade of the Taiwan Strait — which carries 90 percent of the world's advanced semiconductors — based on lessons learned from watching the US struggle with Hormuz.
The Iran war is being fought on Iranian soil. Its strategic consequences may be determined by what Beijing concludes from watching it unfold.