I have a very similar conversation with some of my conservative friends when it comes to international isolationism. We live in a connected world, where what happens in one place can most definitely affect us here in the US. A famine or civil war in Africa creates a refugee crisis that involves us absorbing immigrants who go on to take political power in the US. An eastern European land grab turns into the US spending over a hundred billion dollars. Ragtag militias and pirates in and around the Red Sea interfere with global shipping, causing domestic US prices to rise. Screwing around with biological weapons in China creates a worldwide pandemic* that results in grotesque domestic government outreach and a mandatory vaccine program that not only failed to deliver as promised, but also harmed a whole bunch of recipients.*Well said. If one has ever had almost any policy course then you are familiar with "NIMBYists": Not In My Back Yard. Doesn't matter if it's a homeless shelter or the ultra-communist mayor of a city 3,000 miles away, ALL politics are local in that the trickle-down effects have significant consequences at the state and local level.
Mamdani is a shot across the bow, far worse than a cautionary tale or an idle threat.
Yes, I believe in scaling back our contributions of money and manpower to the rest of the world. But we can't just retreat back into Fortress America. We are the global hegemon, and we have global interests that need to be protected. We just need to be smarter about what those interests are, and how we prioritize them.
*allegedly