Iran delayed encouraging Yemen's Houthi movement to enter the conflict with Israel and the United States until it had already expanded the war across the Gulf and Iraq. After attacks began on February 28, Tehran launched missiles and drones at Israel and Gulf states, mobilized allied militias in Iraq, and supported strikes from Lebanon. It also closed the Strait of Hormuz, signaling its ability to disrupt global energy routes while assessing Washington's appetite for a prolonged fight.

Tehran appears to have calculated that bringing the Houthis into the conflict later would maximize pressure. By opening a potential front in the Red Sea, Iran can threaten another vital shipping corridor and complicate military planning for Israel and the United States. Iranian leaders believe their adversaries have struggled in the past to contain the Houthis, citing years of inconclusive fighting by Saudi Arabia and limited success from previous air campaigns.

The move fits into Iran's broader 'ring of fire' strategy, linking allied forces from Lebanon through Iraq and the Gulf to Yemen. By stretching the battlefield across thousands of miles, Iran aims to demonstrate resilience, deter further attacks, and raise the economic and strategic costs of the war. Even the perception of risk in the Red Sea, alongside the closure of the Strait of Hormuz, could unsettle global markets and strengthen Tehran's leverage.