I would say that the majority of poverty is due to tyrannical governments with absolute power, and these governments are SUPPORTED by nations like the USA and China, they are called "democratic" when they are not, and in exchange for this, American and Chinese interests (among others) have carte blanche to move in and pillage the county's natural resources.
It's the old blame-america-first routine. A very common narrative by the lefties. Let me guess, those third world countries were flourishing democracies before the US got involved.
Take real examples like Italy, Germany and Japan. The US set a democratic regimes and let them go free just as it did in Iraq. It's not the US, it's the political culture of those countries.
The examples you give are substantially pre Cold War,although the onset of that conflict allowed some War Criminals to escape justice.
(Who cares if they are Psychopaths?,They're
our Psychopaths!)
During the Cold War period,the USA & the old USSR supported some pretty horrific Governments,including,on the USA side,Saddam Hussein's regime in Iraq,&,on the USSR side,that of Muammar Gaddafi in Libya.
Of course,the UK & France also got into the act,"white-anting" popular democratic Governments who didn't think giving away their resources for a pittance was a good thing,& in some cases,actively being involved in their overthrow.
It was a fine time for Dictators,though,all they needed was to pretend to "tilt" towards one Bloc,for the other one to be there offering all sorts of inducements.
All those high tech weapons came in very handy for suppressing internal opposition,too!
The USSR even helped the Argentinian Junta in the Falklands/Malvinas War with satellite intelligence.
This,at a time when the Junta was murdering Democrats,Socialists,& Communists in their hundreds.
Of course,the PRC was there,too,supporting one of the most evil regimes of modern times in the form of the Khmer Rouge---they make North Korea look like a holiday camp!
Poor old Saddam didn't realise the game had changed when he invaded Kuwait iprior to the the 1993 war.
The USSR just sat back & didn't interfere when Desert Storm erupted.
People talk a lot of crap about the 2003 Iraq War-----If Dubya had wanted Iraq's oil,he could have made a separate agreement with Saddam to take all the oil they could produce,& broken the back of OPEC at the same time.
George was never that devious a man,though!----I'm sure Richard Nixon in a similar position,would have thought about it!
Of course,the biggest mistake was in thinking "the enemy of my enemy is my friend"!
All sorts of "spivs" were waiting in the wings to take over in Iraq,whilst the "Heroic Mujihadeen" who fought the USSR in Afghanistan quickly morphed into the Taliban!