Yup. And that's why I would not want to see a treaty. Better to have nations acting independently of each other at the policy level, learning from each other's experiences. It's like a market where nations can explore different tradeoffs in how they declare an end or live with it.

What if my tradeoff is "I will partially vaccinate everyone in my country and not perform any surveillance, tracking, or sequencing and stockpile any critical PPE and prohibit export of vaccines"?

Absurd example, but that seems pretty harmful to every country with transportation links to me.

There's the concept of a border. They have liabilities but they have benefits too. We are too used to thinking of them as completely bad.