This is *not* a formulation for peace. It is a formulation for rule by those with the biggest weapons, because they have the biggest weapons.
Obviously, but the threat of nuclear annihilation has limited the scope of confrontation between the great powers to proxy wars.
No problems with the historical facts you cite.
The point made is that the just war principle of a reasonable chance of success required in conducting an ongoing war against an unjust aggressor in Churchill's and Zelensky's calculus are similar in that the necessary cooperation from the U.S., requested and denied, was still believed to be forthcoming.
The U.S. involvement at this point is quite similar to the U.S. involvement in WWII until 1941, e.g., embargo on oil and gas to Japan, freezing of the Axis powers assets in the U.S., weapons shipments to the Allies but no declaration of war against the unjust aggressor.
If you’re seriously suggesting the US formally declare war on Russia, that would be an insane escalation since the US hasn’t officially declared war since 1941, and the Russian Federation has not formally declared war on Ukraine. Such an act of provocation would likely lead to an immediate pre-emptive nuclear first strike which would exterminate the majority of our population; of course we have Credible Second Strike capability with which we could and would retaliate, killing most of their people, but in the ensuing nuclear holocaust it seems unlikely Ukraine would benefit from such a scenario.
When the Pentagon opposes even limited actions like a no-fly zone, we should listen to them. Its not as though they are known to decline an opportunity for military intervention and budgetary increases.
But doing something like formally declaring war would possibly lead to the extermination of the human race, and certainly, it would kill hundreds of millions. The lucky ones would be those in closest proximity to the aiming points of the weapons, because the massive overpressure from the air blast combined with the intense heat would result in instant death. As for those further out, such as in the suburbs of a major city, well, have you ever seen a documentary on radiation poisoning caused by Hiroshima and Nagasaki? Of course, thermonuclear weapons are cleaner, but they are not entirely clean, since they rely on a fissile core as the first stage of the device, which detonates and activates the fusion stages. This still releases deadly radiation and propagates it over a vast instance; in the aftermath of the mishap in testing the first ever nuclear weapon at Bikini Atoll, where the weapon turned out to be much more powerful than projected, nearby Pacific Islanders had to be evacuated and the crew of a Japanese fishing boat unfortunate enough to be downwind of the blast experienced radiation sickness.
Indeed there is an entire field known as Health Physics which exists to study the impact of radiation on the body. Its worth reading up on. Because if you seriously want the Congress of these United States to declare war on what is believed to be the most potent nuclear adversary, I think you should be anle to explain the difference, for example, between Alpha, Beta, and Gamma radiation. Also you should know more about the nuclear capabilities of Russia, whose Strategic Rocket Forces and other nuclear forces are already on alert, and whose nuclear command and control infrastructure seems kind of sketchy, to the point where even at our current level of involvement, the possibility of an accidental pre-emptive launch cannot be excluded (consider the Soviets nearly nuked us by accident due to a software glitch in the early 1980s, there is a documentary on the officer who refused to give the confirmation order to return fire, called
The Man Who Saved the World, which is harrowing and worth a view; he of course was fired and died in poverty around 2010, since this was the Sovietsky Soyuza, and he did violate procedures, which was a cardinal sin).
And He says what to do > 
