So the Americans will bring their ships out of the Persian Gulf &
then attack Iran?
If and when there would be a US strike, this may well take place at a time there are no US carriers in the Gulf. Then again, if one is there, then it could become a case of 'use it or loose it'.
If Iran employs HUMINT around US bases in the Persian Gulf (and I'm sure it does) will have know when/if the vessels leave the Gulf and if they do, then they will know what's up. And afterwards, battle plans will be in full motion (or at least the preparation for war).
Smaller than the Caspian Sea, the Persian Gulf is 251,000 km2
That is still quite a bit of real estate (water) to monitor
How will the US attack from the Caspian Sea?
1) It's land locked 2) They won't be able to exit in time and knowing there is so much place to go, they can be easily tracked by decoy missiles (used as mobile radars) 3) They will be killed
Let's not go into what will happen
if the carries attack...
Duh. They (Tomahawk carrying SSNs and DDGs) would be in the Med, Arabian Sea, Red Sea or possibly even Black Sea, not the Caspian Sea, silly. CVNs would not operate in the Black Sea.
Consider
Diego Garcia - Teheran is 5,165 km (Indian Ocean)
Haifa - Teheran is 1555km. (Mediterranean Sea)
Muscat - Teheran is 1500km (Gulf of Oman / Arabian Sea)
Batumi - Teheran is 1000km (Black Sea)
Jeddah - Bandar Busher is 1400 km (Red Sea)
Block II TLAM-A – 1,350 nmi (1,550 mi; 2,500 km)
Block III TLAM-C, Block IV TLAM-E – 900 nmi (1,000 mi; 1,700 km)
Block III TLAM-D – 700 nmi (810 mi; 1,300 km)
JASSM-ER – 1,000km
JASSM – 370+ km
Combat radius for an carrier-based F/A18E is 390 nmi (449 mi, 722 km) on an interdiction mission, exclusive of aerial refuelling. With 370+ km (230 mi) JASSM that gives a strike range of about 1100km unrefueled.
As for land-based assets, JASSM is also carried by e.g. F-16 (550km + 370 km = 920 km strike range, unrefuelled), F-15E (1,270 + 370 = 1640km), B-1B (5,540 + 370 = 5,910 km).
The 5,540 km combat radius B1's would be adding 1000+ km (620 mi) with JASSM-ER. Eventually this missile also will be integrated onto 7,210 km capable B-52, the 1,270 km capable F-15E, and 550 km capable F-16.