Incoming Zeihan rant:
That was fine strategy 10 years ago when he wrote Accidental Superpower / pre PLA modernization. This is the part where we circle back to developing PRC conventional hypersonics and potential to overwhelm US missile defense, and PRC increasingly able to strike CONUS at scale from mainland - PRC's version of prompt (conventional) global strike which they've been telegraphing development for years. A threat vector US planners are slowly acknowledging. Which means PRC can proportionally deny US energy by hitting critical infra like oil/LNG refineries, huge stationary targets with simple kill chain. Fortress America + shale autarky doesn't mean anything if you can't protect energy security (and by connection of fossil industrial inputs, food security), which is PRC's reverse UNO for the the entire blockading PRC oil strategy, except when applied to US, straight to extraction chain because can't blockade US from US. So next best proportional (even if escalatory thing) is just to make US as vunerable as PRC. All the resources in US sovereign soil is no good if they can't be extracted and made useful to sustain US hegemony. Saudi equipped US hardware learned that lesson when Houthis hit their refineries. Sure Us isn't incompetent like Saudi, but PRC isn't Houthis either, unless you think they actually replaced rocket fuel with water, and used said fuel for hotpot.
Zeihan of skips over the politics in geoPOLITICS when convenient, i.e. US has most waterways, but PRC actually engineered significantly more and uses more internal waterways. US has deep coasts, but PRC dredged her to make way for half of worlds top 10 ports, the other half doesn't contain US. PRC has bad demographics, except PRC has the ideal demographics for geopolitical competition in the timelines relevant to us - set to produce and coordinate more high skilled talent in next 30 years (the cohorts that actually build national power) than US is projected increase population from all sources total, AND declining population of non productive peoples (old, unskilled, unproductive) aka less import dependencies. Declining cohort also has high home ownership and savings rate because frankly they don't expect big welfare net like west. Next 30 years, PRC swapping 50 million STEM talent (already born) with tier1 city earning potential for 100m farmers, migrant workers etc (old -> uneducated die first) that earn 1/10 that. IMO PRC demographic trend (if scrutinized beyond naive pyramid reading) is more pros than cons, especially considering PRC geographic/resource constraint - they don't need 3x more people than the US where only 1x can marginally compete with US and 2x are excess mouths to feed. Better off long term with 2x US population that PRC soil can sustain, where 1.5x can out compete US.
Eitherway the point is frequently politics in geopolitics matter more.
Fortress America has always been part geographic fortress and part artificial, technologic fortress. The entire reason US built/maintains the largest high tech expeditionary military is basically to stay on the front doors of any potential adversaries so they can't get close to CONUS. Let's not forget Continental Navy couldn't hold against out British blockade during revolutionary war without French Navy entering picture. CONUS was vunerable with 1800s tech, it's the technology (politics) part that made fortress america and it's the technology (military) that ensure two oceans are moats. High end missiles circumvents that, hence US unlikely to take out PRC without PRC taking out US unless US engages PRC directly. That's without considering PRC can drag US to fight near PRC home court by hitting JP/SKR/PH to trigger security obligation. Those are island with much worse self sufficiency that'll collapse in 2 months that US is treaty bound to defend. The TLDR is entire Malacca delima / SLOC blockade strategy operates on logic from 10 years ago when US can unilaterally fuck PRC at no _existential_ cost to herself (CONUS), once that logic breaks, blockade becomes unlikely / suicide pact. Question then is what will US/PRC commit suicide over.