This will invite the question: "why didn't they send this to start with?" and the answer ties into something else I've wanted to talk about: The Iranian A2/AD strategy that never materialized. "A2/AD" is a phrase - some say a buzzphraze - meaning "anti-access/area denial." The basic idea is to hold your enemy at risk at long range and force them to fight their way in through a defense-in-depth, best exemplified by the Chinese doctrine in the Pacific. Iran was hobbled by their weak tech base but blessed by the tight geography of the strait and the Gulf of Oman, so their version leaned more towards the attritional defense-in-depth and less the standoff fires, but still had those elements working together. Minefields in a strait work much like minefields on land - once a single casualty is inflicted, the enemy knows its there and will start removing it, so a minefield is only effective if covered by fire. Ergo the much-maligned "red rings of death" maps usually touted when "A2/AD" is brought up usually aren't seen with Iran (in favor of Red Rings showing their ballistic missile arsenal,) but they were theoretically sufficient nonetheless; Iran's SA-20 systems (S-300 PMU-2) might have a notional max range of only 120ish nautical miles, but the distance from Muscat on the Omani coast to Zarabad in Iran is only 130 or so. This is 170ish nautical miles from the strait proper; that's how quickly the geography compresses the battlespace for naval forces. So with S-300s (and shorter-ranged systems to provide layered inner defense against aircraft and incoming weapons) they could throw up a wide enough air umbrella from their coast to give their light naval forces; mainly fast-attack missile boats, room to work. Especially given the heavy civilian traffic in the Gulf of Oman, the small size of their vessels and even land-based jamming support they stood a reasonable chance of making things difficult for an American CSG. The key here is the strait itself; to open it following an Iranian blockade the US would have to get in close; both with aircraft (to do the kind of thorough seek-and-destroy whack a mole required to root out every surface to surface antiship cruise missile launcher and even artillery piece given how narrow the strait gets at its narrowest point,) and eventually with either vulnerable aircraft or ships (helicopter-towed or ship-towed mine sweeps.) So despite the apparent skew of Iranian weapons to close-range instead of standoff; they could expect to pepper the US at range and rapidly increase the presented threat level as they pushed in towards the strait. This has been their obvious plan for decades, as revealed by their force structure and indeed anyone with their resources who had eyes to read a map would've emulated it. They never put it into action. The two biggest reasons for this are the total obsolescence and consequent destruction of Iran's theater-range air defenses and the US/Israel starting the party early with a devastating attack that decapitated almost the entire high-level leadership of their government, paralyzing their command and control. Following the first-ever direct MRBM attack on Israel by Iran in early April of 2024, I predicted a vigorous response, but it was surprisingly more muted - Israel apparently only destroyed the radar of one of Iran's four S-300 batteries with just two air-launched ballistic missiles. Now when it comes to attacking modern SAM systems you've got multiple challenges - the first is getting enough weapons in the air to fight through the defenses because most everything post-80s can (theoretically) engage incoming precision guided munitions, and then you've got to hope your weapons hit the radar/control van to conclusively put the battery out of action (an anti-rad missile will miss by some distance depending on when the radar went cold and/or how good its target memory is, if using cruise missiles against battery components as spotted by ground search radar you don't know which one's a TEL and which one's the radar, precisely, etc.) The April 19th strike by Israel demonstrated that all the above no longer applied between them and Iran. They had weapons the S-300's effectors couldn't engage and Israel's ISR was more than good enough to land pinpoint hits on the radar itself with the first shot. A message was being sent - the air umbrella that enables half your A2/AD strategy effectively doesn't exist to us. The warning was not heeded, and the rest is history. The second factor is the surprise decapitation attack - and this is why the USS Tripoli wasn't already in-theater. I have no doubt they were already prepping and either on standby to deploy or intending to, but the golden opportunity Israeli intelligence cued them to was too good to pass up. And indeed, I think it paid off. The tightly compressed battlespace of the Gulf of Oman actually worked *against* Iran here; typically when you see your enemy flying tons of assets in-theater and moving two carrier strike groups in your direction you tend to deploy your own forces. But given their defensive depth was maybe 100 nautical miles, US forces could be close indeed in a normal sense without being inside what Iran would consider their outer A2/AD perimeter. In short there was plenty of time to "deploy," and esp. since so many of their assets are light or ultra-light ships/boats that can't house their crews for any serious length of time at sea there was no reason to sortie. And when the war started with the decapitation of their entire chain of command, there was nobody left to order those sorties before US follow-on strikes started hitting their Navy at anchor. The Iranians planned to meet the US in the Oman gulf with a horde of missile boats and with the strait bristling with hundreds if not thousands of mines behind them... but it turns out that an anti-access/area denial strategy doesn't work very well when your enemy's already accessing the hell out of the area you wanted to deny them by the time you get your pants on.