Tragedy of John McCain's life is that for decades he was Washington's loudest promoter of unwinnable wars, making him a mortal threat to the people and country he purported to serve. While wasting his own life McCain helped destroy so many others. He protected financial interests of US elites and Endless Unwinnable War Industry-Raul Ilargi Meijer

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"Regarding 2003 Iraq War, McCain "wrote in his 2018 memoir The Restless Wave that "The principal reason for invading Iraq, that Saddam had WMD, was wrong....The war, with its cost in lives and treasure and security, can't be judged as anything other than a mistake, a very serious one, and I have to accept my share of the blame for it.""
 
May 14, 2018, "John McCain: A Life Wasted?" zero hedge,  Authored by Raul Ilargi Meijer via The Automatic Earth blog

"What’s happening to John McCain is tragic. It’s not something one should ever wish upon another human being. Nor is it decent, let alone useful, to wish that he would die. Wishing bad things upon someone because they did bad things is too close for comfort to what he himself did. But it’s good to remember that his brain tumor is not the most tragic part of McCain’s life on earth. And no, neither is his time as prisoner of war in Vietnam.

McCain’s main tragedy is that he didn’t learn the one lesson he should have learned about his time in Vietnam, and didn’t turn his back on warfare. Instead, he turned into the biggest and loudest pro-war campaigner in Washington for decades. Talk about a missed opportunity, a life wasted. If there was one person who was presented with the first-hand experience needed to turn against bloodshed, it was John McCain.

What’s more, during his time in the House and later the Senate, McCain completely missed out on a development that might yet have changed his mind. That is, wars became unwinnable. Something even that the US losing their war in Vietnam might have taught him. It entirely passed him by. McCain still never saw an opportunity to wage battle somewhere, anywhere on the planet, that he didn’t like.

That makes him a dinosaur and a fossil who should never have been allowed to remain in the Senate for as long as he did. At the age of 81, and after ‘serving’ for 35 years in Washington, it apparently becomes too difficult to see how the world outside changes, let alone to adapt to those changes. If you limit the time a president can serve, why not do the same for senators? Is it because those same senators would have to vote on that?

Moreover, if wars are unwinnable, but you incessantly call for new wars anyway, then regardless of moral issues about going to war in the first place, you have de facto become a threat to your own people and your own country that you purport to serve. Especially, and first of all, to the American soldiers you desire to send out there to fight those wars. But also a threat to the image of America around the globe.

When wars are unwinnable, there is no reason to fight them. Again, even apart from morals and ethics. You will have to find other ways to deal with ‘elements’ that feel and act less than friendly towards you. To find out what, it helps to realize that they understand it’s just as futile for them to attack you militarily as it is for you to attack them. It also helps to figure out why they are unfriendly.

What doesn’t help is to take yet another stab at Putin and say “Vladimir Putin is an evil man, and he is intent on evil deeds”, as McCain does in a forthcoming book. If that’s the best you can do, your best-by date has long since passed. That’s language fit for a 4-year old. And George W.

McCain’s father and grandfather were both 4-star US Navy admirals. Perhaps that partly explains his blindness to the evils of war, and the role the US has played in many conflicts, including -but certainly not limited to- Vietnam. It’s hard to imagine Apocalypse Now, Platoon or Full Metal Jacket being McCain’s favorite Hollywood classics.

And that is a bigger problem than it may seem. Because America has indeed been able to paint a vivid portrait for itself of why Vietnam was such an insane venture that should never have happened, and certainly not repeated. If your culture has the ability to put that in words and images, and as a nation you still don’t learn the lesson embedded in them, you’re pretty much lost.

Oh, and besides, you lost too, remember? You lost the war and the lives and limbs of tens of thousands of young Americans and over a million Vietnamese. To have been part of that and then turn around and strive to be Washington’s premier warmonger, that’s just totally bonkers. Or worse. Has McCain been promoting war all this time because he subconsciously wanted to redo Vietnam but this time not lose?

Unwinnable wars are bad news for the weapons industry. They will deny the existence of even such a concept as long and as strongly as they can. Because if you can’t win a war, why wage them? There will continue to be technological developments, but there’s no “throughput”. You can fire some missiles into some desert somewhere from time to time, and that’s it.

The military-industrial complex is happy only...if and when guns and missiles and jets constantly need to be replaced because they’ve been lost in a theater of war, along with young Americans. McCain knows this better than most. And he knows the captains of this complex, both the military side and the weapons producers. Far too well.

Being as beholden as it is to the arms makers and dealers, has made America lose whatever edge it once had militarily. In the US weapons are developed and sold to generate the largest profits possible; in Russia, they are developed to protect the country. This is largely why the American defense budget is 10 times larger than its Russian counterpart. All this happened on John McCain’s watch. 

The entire narrative of "protecting and sharing our values" has become hollow propaganda. Because the US has engaged its military in more theaters of war and invasion than we can even keep track of anymore. The US armed forces don’t protect democracy or human rights around the world, they protect the financial interests of America’s elites, including the military-industrial complex. Does anyone believe John McCain doesn’t know this?

Unbeknownst to John McCain, the world has entered a whole new era. And this didn’t happen yesterday. Russia and China may have only recently announced new hypersonic missile technology, but it didn’t fall out of the sky. It does profoundly change things though. It ends all notions and dreams of American exceptionalism and unilateralism.

And America needs to learn that lesson. It will have to do it without John McCain. And it might as well, because McCain was incapable of changing, and of seeing the changes around him. But the American view of the world will have to change, because the world itself has.

Still, you’re right: the real tragedy is not that John McCain wasted his own life. It’s that he helped destroy so many others."