PRC is essentially calorically food secure (with huge waste / room to optimize), has large energy reserves, and unlike island nations, massive domestic raw resource supplies. PRC is NOT Japan during WW2. Hence PRC is much more autarkic and can drag on war economy, perhaps indefinitely. Sure people will eat less meat and depend more on EVs (maybe even cope on bikes) during transition, but when shit hits fan, PRC + RU (is a powerful self sufficient land bloc with much greater long term war making potential than US partners trapped on vunerable islands. It's about asymmetric vunerability.

>The issue is in such a war China is also cut off

The Malacca dilemma was based on assumption that US had unilateral power to blockade PRC imports with impunity due to being domestically energy secure - it was an argument/strategy also based on asymmetric vunerability.

But that's increasingly not true, the TLDR is PRC rocket force likely already has capability or will in short term to _conventionally_ strike major US energy infra... US is existentially dependant on ~150 refineries - they are as dependant on these refineries as PRC is on maritime energy shipping. People conflate resource security as having more resources in your soil but it's really about the ability to protect the critical extraction/delivery infra. Otherwise Saudi wouldn't bribe US for security. Obviously conventional CONUS strikes is also a prelude to MAD, but it is also an equation for PRC establishing mutual vunerability with US, which greatly constrains US actions. Not to mention such capability also functionally dismantles US naval supremacy via port strikes (both capital and support assets) that underpins US global power projection.

My feeling is that the chance of US blockading PRC when she becomes as (conventionally) vunerable as PRC is increasingly remote. It's hard to understate how much geostrategic calculations must change once a relatively autarkic industrial power as massive as PRC is able credibly bring actual war to US homefront. It will be first time in modern history where conventional fires can penetrate CONUS to meaningfully degrade US society. US will have to assess whether it wants to fight a possibly existential war (possibly at best a pyrrhic one where she might not uphold her hegemony after) or abandon East Asia where PRC preponderance is increasingly difficult to match or deter, especially with respect to TW.