If your argument is that tariffs don't disincentivize behaviors because the government is just that bad at collecting taxes, you're not really in step with reality.
In fact other governments in a game theory like ploy to get ahead of your country may agree to international agreements that they know they can game to their advantage.
The fundamental assumptions are wrong. You're not in this together. All countries are in direct competition, and some a more cut-throat than others. If potential disaster B is coming irregardless, country B can position themselves to come-out on top of country A when it does.