You are a Nato spokesperson without looking at PLA of ChinaIf Iran sink 1 Carrier (let's assume they can do that) that would mean US will basically send EVERYTHING they have in the region to have a free for all, they won't move anything off outside Middle East area (There are 2 Fleet and 7 Airbase in the Middle East, more than enough naval and air power to destroy Iran if that happened)
China attack in South China Seas will be South East Asia problem, unless China attack Guam or Hawaii, which will trigger NATO article 5, so China will no longer be just attacking the US, but will be against the entire NATO. And Russia war in Ukraine is also not US direct engagement.
& Russia nukes & South Korea / North Korea Nukes & Pakistan/ India nukes.