The size of a nation doesn't inherently determine the success of socialism. There have been historical examples of relatively small nations with socialist-inspired policies and economic structures that achieved positive outcomes.

Ok, so its not size that is the issue.

I was moreso making the point that nations are different from communes existing within capitalist nations on a variety of levels.

Yes, I get that is the point you want to make but I am inclined to not believe you, since it sounds way too convenient. "I can't show you a small scale proof of concepts because evil capitalism exists." So my question is, what exactly are the issues? Concrete examples.

For taxes, while infrastructure and services are vital, a truly communist system wouldn't depend on taxation in the traditional sense. The idea is for the community to directly produce the goods and services it needs. Again, this runs into conflict when a commune needs to exist in a capitalist framework.

Ok sure, but that does not prevent a commune from existing. If it can produce enough economic value, it does not matter if it builds infrastructure itself or pays taxes. Just treat the commune like a micro-nation that can't produce firetrucks and bulldozers and has to obtain them from abroad by bartering using money as the medium.

The challenge lies in managing the complexity of large-scale bartering or exchange systems on an international level, but it's not necessarily impossible. For a small commune in a capitalist nation, though, I can't see that ever happening.

Why? International trade is already pretty much barter facilitated by money. Why couldn't a commune treat the surrounding system the same as a foreign nation from trade perspective?

Trade and international exchange would likely be based on cooperation and needs fulfillment instead of pure profit motives.

So a communist nation can't peacefully coexist and cooperate with any other system? Doesn't sound very robust.

For the legal stuff: you're right! Legal structures exist to support collective ownership (co-ops, land trusts, etc.). The issue is how those structures interact with a dominant capitalist system and its legal frameworks.

What exactly? What laws would we need to change to make this possible?

For anticommunist interference, yes it is illegal but when has that ever stopped anyone from harassing their political opponents?

Sure, it can't stop it but it can limit it. Again, if your system falls apart due to little push back, its not a very robust system.