Iran has deployed a large fleet of small, fast watercraft in the Strait of Hormuz, effectively disrupting commercial and military passage through one of the world's most critical shipping lanes. The move follows the near-total destruction of Iran's conventional naval fleet in US-Israeli military raids.

The vessels, described as "mosquito boats," are small enough to evade many conventional naval defense systems but numerous enough to create serious obstruction across every major passageway in the strait. Without a traditional fleet to project power, Iran has shifted to a swarming strategy using low-cost, fast-moving craft that are difficult to track and neutralize at scale.

Why the Strait of Hormuz Matters

The Strait of Hormuz is the narrow waterway between Iran and the Arabian Peninsula. Roughly 20 percent of the world's traded oil passes through it, along with significant volumes of liquefied natural gas. Any sustained disruption to passage there ripples quickly into global energy prices, shipping insurance costs, and supply chain timelines for oil-importing economies, including India, Japan, South Korea, and much of Europe.

Iran's use of small boat swarms is not a new tactic, but its application at this scale, after the loss of its larger naval assets, represents a deliberate pivot. A conventional navy can be targeted, disabled, or sunk through airstrikes or missile attacks. A distributed fleet of small, fast boats is far harder to neutralize in one operation. Each boat individually is low-value; collectively, they can block, harass, or threaten vessels far larger than themselves.

The strategy also lowers the cost of confrontation for Iran. Building and crewing a mosquito boat fleet requires far fewer resources than maintaining frigates or destroyers. Iran can sustain the pressure even while rebuilding other military capabilities, making this a durable disruption tool rather than a temporary measure.

What Changes Next

The immediate effect is on commercial shipping. Vessels transiting the strait now face increased risk of harassment, boarding, or delay. Shipping insurers have already been adjusting war-risk premiums for the region over recent months, and a sustained small-boat blockade is likely to push those costs higher. Tanker operators may reroute around the Cape of Good Hope, which adds weeks to voyages and raises freight costs significantly.

For global oil markets, prolonged interference with Hormuz transit could tighten supply and push crude prices upward, particularly if major Gulf producers cannot reliably export. Saudi Arabia, the UAE, Iraq, and Kuwait all rely on the strait for a significant share of their oil exports. Any persistent disruption affects their revenue and production incentives.

US and allied naval forces in the region face a tactical problem. Countering a swarm of small boats requires sustained patrol presence and rules of engagement that are difficult to apply cleanly in a congested waterway. Escalating against individual small craft risks incidents that widen the conflict. Ignoring them allows the disruption to continue.

Iran's conventional naval losses, which would normally represent a major strategic setback, have effectively been converted into a different kind of leverage. The mosquito fleet cannot win a naval battle in a traditional sense, but it does not need to. It only needs to make the strait costly and unpredictable enough to keep pressure on global shipping, energy markets, and the diplomatic calculations of every country with a stake in the region's stability.

The next key indicators to watch are tanker diversion rates through the strait, changes in shipping insurance premiums for the Persian Gulf, and any response from the US Fifth Fleet or allied navies currently operating in the area.