Under what political economy? Capitalism. Humans need infrastructure. Concrete is currently (and likely will be for a long time) needed to build infrastructure. A model of environmental protection that ignores human needs is going to be problematic.

As for war, see above: capitalism (or, rather, class society) is the cause of war. Capitalism is in constant crisis. Of overproduction or underproduction and of the surplus capital absorption problem. Capitalists need war not just to defend capital but as a fundamental building block of capitalist relations.

World War Zero (the wars over African and/or Asian colonies, depending on who you ask), World War I, and World War II were all fought because mainly European (and Japanese) colonial-capitalists ran out of room to expand (resources, labor, and consumers). And if capitalism needs anything, it is constant room to expand. Hence the capitalists salivating at dividing up Russia, China, Cuba, DPRK, and previously the USSR. (Hence, too, the US salivating at carving up and cannibalising Europe, currently.)

Depends what you mean. If you mean states governed by communist parties, obviously no. But again, that’s the wrong question. The correct question is, Why? Answer: the global political economy is capitalism. Pretending it doesn’t exist and doing your own sustainable thing is not an option. As above and below: the threat of capitalist restoration. Those who don’t play along have three options: horrific sanctions, horrific war, or both.

The same does not apply both ways. Imperialists are not invading the global south because they are scared. These are wars of aggression. I’m not talking in hypotheticals. I’m not writing a rioter’s charter. I’m referring to well-recorded and publicly available historical records.

Chile, China, Cuba, Ghana, Indonesia, Korea, Laos, USSR, Vietnam, and more. What do these states have in common? Every single one was either invaded and/or subject to coups supported by foreign powers and/or destroyed by those foreign colonial powers/imperialists. Why? Because they wanted independence and socialism/communism.

(I don’t have the character count to talk about all the states that were invaded, destroyed, or subject to coups simply because an imperialist or colonialist liked the look of the resources. It’s a long list.)

Which of those states survived? China, Cuba, Laos, DPRK, and Vietnam. Why? In part because they fought and did not forget the threat of capitalist restoration. They developed industrially/militarily to deter the imperialists from invading.

The shoe does not fit the other foot because the other similarity (except for some few USSR actions) is that none of the above states, once established, threatened war to overthrow capitalism (no, I don’t consider the USSR fighting the Nazis back to Berlin or supporting anti-colonial movements to be the same thing as the threat posed by capitalists).

You’re slightly missing the point, there. Capitalists don’t just ‘buy’ things from the global south as if there’s a magical market of producer states and purchaser states. Capitalists largely control the economies of the global south. That’s what imperialism means. It’s what the IMF, World Bank, WTO, and US military exist for. A good book on this is Zac Cope, The Wealth of (Some) Nations.

The exceptions are, again, the states governed by communists, which have either been sanctioned almost to death (e.g. Cuba, DPRK) or played along in order to avoid sanctions and invasions (e.g. China, Vietnam).

(Neoliberal) capitalists exported much of their industrial capacity to their neo-colonies and to independent communist states who played along in order to advance their own development. It’s not feasible to opt out of capitalism. The best one can hope for is to be sanctioned like Cuba and the DPRK.

This does create some impetus e.g. for China to allow for-profit corporations to operate along capitalist lines. And no, for-profit corporations do not operate for the common good. They, to reiterate, operate for profit. This follows the logic of the commodity form, which determines global political economic relations. The difference is that the CPC has power over Chinese companies. It’s the opposite practically everywhere else, where corporations (well, their owners) control the state/government/political parties by various means.

Importantly, China (which is the one that gets all the bad press for pollution) has a communist party in charge. Yes, they use(d) capital to advance. But only as one tool in the path towards a higher stage of socialism. Which is why, now that they have caught up and in many ways surpassed the industrial and technological capacity of the imperialists, China is rapidly shifting to a green economy, building solar, wind, nuclear infrastructure, etc, and phasing out dirty coal for super efficient coal plants.

To emphasise a point from above, it’s not an option, yet, to just turn off emissions; but emissions can be lowered and balanced out (through something more meaningful than western ‘carbon credits’). And China is doing that, because it is not in thrall to the profit-motive.

I don’t know what you mean by a ‘pure economic system’.