As US Ponders Responses, Two Red Lines Collide

The US promises some kind of response against Iran after the deaths of three US servicemembers in Jordan. The big question is how aggressive it will be.

• Red line, I: The most aggressive option would be to hit Iranian targets within Iran itself. However, this one carries the greatest risk of escalating things into a regional war. As Politico puts it, the "Iranian government, for its part, has suggested that a strike on Iran itself would be a red line." Of course, the US has a red line of its own—the killing of US troops—and hawks in Congress and elsewhere say a strike inside Iran is necessary.
• Red line, II: "We've allowed ourselves to come to a point where now, direct strikes on Iran are what is required to quell this activity," John Miller, a retired Navy admiral who commanded the US Fifth Fleet in the Persian Gulf, tells Foreign Policy. "In true Iranian fashion, they're going to push and push and push, until they sense that they've come to a red line. They do that themselves. They do it through their proxies. Well, they crossed the red line," he said, referring to the killing of US troops. "They need to be held to account for that."

• Unprecedented: The Wall Street Journal notes that while then-President Reagan struck Iranian ships and offshore oil platforms in the 1980s, the US "hasn't previously attacked attacked targets on Iranian territory." The story notes that then-President Trump called off a planned strike inside Iran in 2019 after Tehran shot down an American surveillance drone.
• More likely: The drone that killed the US troops came from an Iranian-backed group in Iraq that operates as part of Iran's "Axis of Resistance," per the Conversation. Think Hezbollah, Hamas, and the Houthis. Many observers think the US will strike at these proxies, perhaps in Iraq or Syria, rather than in Iran.
• Options: The Atlantic Council rounds up scenarios: The US might hit Iranian ships in international waters, Houthi leadership, or target Iranian personnel (not just proxies) in Syria. More specifically, the US "could deliver a strategic blow to Iran's capabilities in eastern Syria, upending the strategic Iraq-Syria-Lebanon land corridor," says one of the analysts quoted. The least aggressive option would be to forego a military response and double down on finding a diplomatic solution with Iran, and Foreign Policy digs into that.

(The attack on US troops took place at a remote outpost called Tower 22.)