To add on what @bewildered posted. A MEU is about 2200 Marines with only a single Marine Infantry battalion with ~600 Marines. The remaining 1600 are artillery, maintainers, aircrew, supply, communications, etc. There's another MEU and what looks to be a Brigade Combat Team (BCT) from the 82nd Airborne Division headed there as well. Based on the amount of actual infantry soldiers/Marines and the kind of equipment these units have, they could conduct raids, but have nowhere the manpower or logistical tail to take and hold any significant amount of contested territory. Especially on the mainland. There's media speculation they're tasked to take Kharg Island. You could raid the island with a MEU, and depending on what defenses Iran has placed on the island you could take Kharg Island with a MEU, but holding the island long term is problematic. To do so would likely subject those units to defending against a siege. For those not familiar with Kharg Island. It's only about 15.5 miles from the coast of mainland Iran. Well within the range of artillery and air defenses on the mainland. Those reasons will make resupply problematic. It's also almost due east of Kuwait City, so any shipborne reinforcements/resupply must transit the Strait of Hormuz and then sail the length of the Persian Gulf. Aerial resupply would be vulnerable to Iranian air defenses on the mainland. Qeshm Island off Iran's southern coast (pretty mush in the Strait) has also been reported as a possibility. Its not an oil production node, but historically where Iran stores cruise missiles, mines, etc., to stage attacks from against ships transiting the straight. It is also close enough to the mainland its within mainland artillery and air defense ranges. A third option media has talked about are raids against nuclear sites. These sites are all deep in Iranian territory. It's possible, but what's the risk vs reward? Especially since all these sites have been struck by airstrikes.