Exactly, what are we going to do? Impose sanctions? Tarriffs? We do that anyways without recourse. Bomb you? We might do that anyways without reasonable impetus. Y'all have no reason to temper your actions for fear of retribution; our President is threatening to rename a lake to Lake America because we "won't be doing business with Ontario anymore". Why? Does it matter? Could anyone have done anything that wasn't just abject groveling? No.

To hell with us. The rest of the world needs to move on from giving a crap what our government thinks of you.

The US is fighting wars with everyone on everything at the same time. They don't have the resources to do anything about it. Every country will develop their own independent payment networks.

China was right to block US tech companies to promote their own, most large and capable countries will do the same over time.

Doctorow's point is that the USA's trade policy is unilaterally capricious and malevolent toward the best of its allies, so other nations' actions ultimately cannot be said to have any mitigating causal effect. Might as well just go for it. F the DMCA.