Who knows what Allende may have done differently if given a second chance?
But you have to consider that he won with the people's support. In fact, despite all the dirty tricks of the United States, which included economic warfare, sabotage, and murder - his party gained seats in the Parliamentary midterm elections just before the coup. That's what really sent Nixon, Kissenger, Pinochet, and the others over the edge.
The plain fact was that Chilean society, as in Argentina, embraced developmentalist and socialist policies. It was true throughout their society. It was a part of their music, poetry, writing, religion, and history. I cannot pretend to know what went through Allende's mind, but I think that maybe he was sure that the people's faith in him and the Chilean democracy would prevail.
Of course history proved that theory incorrect. And you're right, this is the country that appointed Nazis to prominent positions in West Germany. We put Korean sympathizers with the Japanese occupiers - men guilty of heinous war crimes against their own people - in charge of the South Korean Army. Many of them later ran the country as brutal dictators. We threw out democratically elected leaders in Iran, Chile, and Greece in order to replace them with some of the world's most disturbing police states.
But we were very good at it. Look at the people convinced that this is the country responsible for "spreading freedom?" Or, as Sirs once said, that this country always has the best intentions. We toss in the catch phrases of "freedom," "liberty," "democracy," and until very recently people eat it with a spoon.
Maybe money talks, maybe we're that good at PR, maybe we made good Imperialists for a few decades there. I don't know. But for whatever reason Allende and many more in Latin America suffered horribly for it.
A real hero of mine (maybe my only hero, as I don't have many) was shot while consecrating the Eucharist in El Salvador by a member of a right-wing death squad. Anyone who spoke of the plight of the poor, equality, or justice was automatically a communist and enemy of the American Government and consequently the military juntas we placed throughout those nations.