Most people lock the doors of their houses but not the doors of the rooms. Citizens of EU countries can freely move within EU borders, citizens of most of the other countries need a visa to come. I will lend money to my acquaintances but not to strangers.
Most countries have military forces, some crime rates, some tricky business legislature, inspections of all sorts.
Surveillance, security, tragedy of the commons.
Seems like humanity has more problems with itself than with the environment (diseases, cataclysms, etc).
We have met the enemy and he is us.
We’ve come a long way, sure. We don’t kill each other as much as we used to. We have countries instead of tribes. We have international collaboration in many fields.
And we have a long journey ahead of us.