This general principle applies to a lot of seemingly-irrational government action: it's effectively buying insurance. We all understand that, in an ideal world

This general principle applies to a lot of seemingly-irrational government action: it's effectively buying insurance. We all understand that, in an ideal world, most forms of (consumer-focused) insurance are a blackhole that you dump money into and never actually get any money back, because insurance only pays out if things go awry. Subsidising strategic industries like farming falls under that exact same rubric. Ideally you don't ever want to cash in on that investment, but it's important that it's there. The CHIPS Act in the US is an example of this idea exactly. In a world where China is getting more aggressive around Taiwan, US-based foundries are an (expensive) insurance policy.