The country will often do that whenever there isn't an strong leader in charge or government's shaky rather than solid. Right now it's rock solid, and their economy was already slated to stall. This has only given them a scapegoat. 

Except when it wasn't. It wasn't America who launched the first satellite and it definitely wasn't them who put the first man in space. Doing something along the lines of visiting another world years later doesn't change the fact Armstrong landed years later when technology had progressed (and when the Soviets had no reason to prove anything to anyone). 

Besides, more advanced technology didn't always have better results. The Americans witnessed how somehow outdated Soviet technology was superior at times. 

Also, why worry of how supplying weapons and transport changed things when the ones using them to great effect were the Soviet troops? Have you forgotten it was they who were marching down Berlin? Or how much of the industrial capacity they had built was effectively destroyed because they were caught with their pants down? Or that their economy was still recovering from a power vacuum? More importantly, do you realize the vast majority of the resources provided by the lend lease were rations, ammo and transport? Little actual combat equipment was used. The US provided logistical support since the USSR had most of their industry destroyed in the West and they only had one line in the Far East! Look at the descriptions! Most of the shipments were trucks or food or ammunition (or tires)! 

It was only one third of it. Given they were fighting two heavy hitting countries at once (and that these same countries were giving the rest of Europe a headache even worse than theirs) I think it's safe to say no one would have been able to come out on top on their own. The US was necessary because their industrial capacity was safely tucked away in another continent. Thus they had the ability to support the European effort. Also, initially, much of the goods came from the UK, who was also being bombed to kingdom come. This war was impossible to win on their own. It doesn't lead to people thinking if the USSR hadn't existed the US could've just stepped in to destroy everyone... 

At the end of the day this hardly changes anything. The USSR were the ones who invaded Germany and destroyed their troops with their tanks, their soldiers and their aircraft. Most American support was specifically support. The Americans weren't marching alongside the Red Army, were they? 

Had Germany gone all out on the USSR they might have lasted longer, but even twice as many soldiers (the amount contributed by the collapse of the Western front) would've led to them getting closer to Moscow (they were close) and perhaps seize the only city left in the way, but the amount of Soviet forces who were preparing for the counter offensive was humongous! 6.6 million soldiers don't go down easily.

1. The Taliban didn't have free money from other countries for being freedom fighters, but since you insist, why not do what everyone else has done to death and compare it to the Vietnam War instead? 

2. The mass deportation and terror of the raids in the years leading up to the war left the Red Army without an effective high command. Most lieutenants and marshals were stumbling around in the dark and had no previous war experience compared to the former aides of the party at the time. They literally lost because there were only stupid numbskulls running the circus... 

Yes, Stalin did something really stupid when he sacked the military's top ranking officers and then told everyone they were going to war. 

3. Before Germany was a Superpower. Now they might as well have no military... 

I don't think you ever read that US military killed dozen or hundred thousand of their soldiers for retreating in a war. Or killed a lot of high ranking officials merely on a suspicion of coup d'etat.

What did US do to its citizens that equate to the famine Stalin inflicted on Ukrainians?