IMO, the US should publicly commit to a solid order for a very large number of the weapon systems Taiwan and Ukraine would likely need in an extended double conflict. We saw in COVID (with things like tests) that "we need a billion of X, but we'll dribble out the order in much smaller quantities" tends to make industry leery of evaporating demand after making big capital investments.
https://pbs.twimg.com/media/Fmc_WJsWAAUP8GL?format=jpg&name=...
We can ramp up Javelins faster than China can amass landing craft in numbers large enough to make invasion feasible.
China would completely swamp our manufacturing. However, they only have a small stockpile of the raw goods needed to keep up their current manufacturing levels. Even for something as basic as steel, which China's overwhelming dominance in is widely known...they are very limited by foreign imports of iron (75% of their domestic consumption of iron is provided by Australia). If China had to stop imports from Western nations, its war material production capacity would probably drop by about 75% after its 30-90 day stockpile of raw materials was used up.
How much America's production suffer without good from China? Probably fairly catastrophic as well, but more especially in the long run as industrial parts break and need replacement. The resultant domestic shortages and inflation here would quickly ruin our populations appetite for any major trade war over a small foreign island.
That’s a fair point, but US geopolitical decisions have incentivized an extremely close relationship between China and Russia, which has the third-largest iron ore reserves globally and is one of the largest producers of many other raw materials as well.
While we’re comparing Ukraine and Taiwan, Taiwan has significant defensive advantages; tougher terrain, no land border, and they’ve been fortifying for decades. Even river crossings in Ukraine are fraught with peril, let alone an ocean strait.