The USN isn't really up for threat just yet. They still have more carriers than the rest of the world combined, and their half has twice the tonnage as the ROW

The USN isn't really up for threat just yet. They still have more carriers than the rest of the world combined, and their half has twice the tonnage as the ROW half. Admiral Kuznetsov, Russia's one carrier, is 55kton. The ten US Nimitz-class carriers average around 105kton. Take away the carriers from the US's allies, and you have a total of around 7 (to the US's 20-odd) - and these non-allied are generally around 25kton (China and Russia have one carrier each at around 55k). The US is a long way from being realistically challenged at sea. Russia's "power projection" in Syria is only a short distance from its supply ports in the Black Sea. The US can put a carrier group anywhere on the planet (well, on the watery bits) and keep it there; neither Russia nor China can do that, either militarily, or politically (local supply).