It doesn't matter if it was ethically justified or not. The fact remains that the assets were frozen by the US government which runs contrary to the notion that the US allows unrestricted capital movement. Today it's Russians' assets, yesterday it was Afghanistan's central bank's assets and tomorrow it can be any other country

> tomorrow it can be any other country

US can even invade any other country tomorrow. There are risks everywhere, every country has to evaluate "Do I need to insure myself against US invasion / asset freeze in the next 5 years? How much will such insurance cost?". Unless you plan to invade your neighbor, the chances of such events are pretty low and the cost of insurance usually does not outweigh the benefits.

I assume you'd deliver fuel to the Japanese Empire until they directly attacked you. Or maybe even later, after all deals have to be kept right?

> I assume you'd deliver fuel to the Japanese Empire until they directly attacked you

Japan attacked because they were running out of fuel and had to act quickly (either strike, or back down in China which they didn't want to). Without an embargo, they would have just continued their war in China.

It would surely be better to allow genocidal empire continue to expand, rather than profit selling them goods for a decade of genocide?

You are mixing up the order of events here.

I assume you would be fine with the US assets being frozen by the rest of the world for unprovoked aggression on Iraq?

Yeah. The 2003 one, 1991 was totally fine.