Not necessarily declare war, but US+JP forces at a minimum are absolutely considered H+0 targets in the event of a conflict. Giving us time to reposition, withdraw and disperse assets, and time to elevate our readiness is a huge disadvantage in the event that we do intervene (Even in the course of a single day, our forces can drastically complicate PLA ISTAR and weaponeering). If the PLA is committed to reunification, we currently do not assess that they would afford us the advantage of free time. The best time to kill something is when it's unprepared. Allowing us any time at all would be a significant blunder in the event we do opt to intervene - which I can confidently say is extremely likely in our current geostrategic environment.
That's the current time when they probably do need a surprise attack against US/JP forces to create enough advantage.
Let's forward 8 years to 2030. I'm not saying this is going to happen, but let's just play this out hypothetically. China has 4 carriers in service, 20 H-20s, 6 to 8 095s, 20 055s, 6 075/076s, 150 Y-20s, 50 Y-20Us, full arsenal of hypersonic/subsonic anti-ship/land attack missile + 600 J-20s and 50 J-35s. At the same time, US military has a very small number hypersonic missiles, minimal B-21 in service, no NGAD, 10 more block V Virginia class, very few block 4 F-35s. So, PLA in this case has huge improvement vs now and US military just proceed as it has been in the past 8 years. And let's say PLA has this unmanned stuff figured out better than US military.
All of this is quite likely imo, I don't know how you would judge this. But let's say this happens, wouldn't the foreign policy people even hesistate against this type of odds and be cautious in entering any conflict? Seems like the smaller the gap is between the 2 militaries, the more beneficial it is for PLAAF to not do pre-emptive strike.
NATO doesn't need to be in the Pacific to play a non-trivial role in the conflict. Even if we laugh at attempts like this
In a wider conflagration, NATO stopping China's trade with Africa and Middles East is something that China doesn't have an answer to at the moment.
Are you just think about natural resources? In a couple of years, there will be so many EVs and renewable energy in China + with supplies of oil/gas from Russia that getting cut off from Africa/middle East is going to do very little in stopping China's industrial power. Japan/SK and all of ASEAN countries would actually get destroyed by that though.
If Europe does that, China can always send bombers in to destroy refineries/LNG production in middle east. Then, Europe would be really in trouble. Without Chinese supply chain and fossil fuel, the European economy is going to collapse.
