As we all know, the key Western militaries (primarily US, FR, UK but not only) would come at this a different way, with air dominance. Full air dominance would give two options for a frontal attack (as opposed to going around the back with amphibs):
1) Take out all artillery, choppers, fixed wing, missile systems, within 50-100 miles or much more.
2)a. Either then pick out the minefields 100m at a time, one lane at a time, one rocket or flail at a time, with only limited localised short lifespan opposition, then pour through; or
2)b. Go over the top with heliborne assault outside MANPADS range (and larger SAMs already out) to behind the fortified belt, then backfill towards 2a.
A helicopter air mobile assault would be a temporary hold on the territory on the other side, but air lifting heavy equipment and the supplies to keep them moving would be difficult.
I think an amphibious operation would be risky. Amphibious operations against a continental land mass has more risk than an island which can be isolated more easily and while the US does train for amphibious operations, it hasn't actually conducted a landing that could be opposed since 1950.
Establishing air supremacy would help a lot, but it would not be a smooth operation like the Gulf War.
And as we know, neither of these options are available to Ukraine, nor is the enabler of full air dominance. So Ukraine is having to do this the very hard way. Which is precisely why Russia laid all these mines and built the trench/etc systems - the Russians are no fools and have themselves thought this through.
Our job here is to keep the strategic resolve in the West. Which means inserting spinal reinforcement into our politicians at all opportunities, and making sure our fellow voters understand the implications of their votes. Fortunately the Fance, Italy, and German electoral cycles are done with for the next 3-4 years. And in the UK there is very solid cross party consensus which is relevant as there will be an election in 12-24 mnths, but UKR will not be a direct issue. However USA is a different issue, and that is the 18-month gate that Putin is playing for and hoping to get.
From what my partner was reading about leaks from inside Russia, Putin is nervous now that Trump got indicted on charges of trying to overthrow the government. Additionally a lot of Russian news commentators are bewildered why Trump didn't throw all his opposition into prison when he was president. They don't really grok how rule of law works.
The US election next year is probably going to be pretty weird, but I think chances are that the US will continue to back Ukraine is good. It's still an unneede distraction when the world needs to stay focused on the goal.
Regarding mines: major disagreement with you here. Take the DMZ between South Korea and North. It is a solid 2.5km of mines with both sides mining flat lands suitable for equipment to a much greater depth. That's 160 x 2.5 miles. The USA designed the minefields.
You're right, that one slipped my mind. But the DMZ minefield has done its job. No military force has tried to cross that border in 70 years.
Egypt had done the same during campaigns on the Sinai. Russia paid attention and while Iraq did a terrible job laying minefields the Russia ones are done properly. Have you seen the videos of the russians laying mines? Truck drives across field, 2 guys in back drop mines every 5 feet in two rows, turn around, repeat, turn around and repeat.
Anyhow, it is clear that russia/USSR did anticipate needing millions of anti-tank mines because they had them in stock. If someone has millions of weapons in stock it should be at least a consideration.
Taken altogether we have this: the USA has designed and implemented minefields of over 300 sq miles in depths up to 5km deep. Minefields historically were quite effective in use by Egypt but could have been more so if laid more densely. Russia had millions of mines. We saw them laying the minefields.
Mick Ryan has it right in a recent substack, the west needs a new solution for minefields. Lastly and saying again...the generals in charge of the south were not idiots. I continue to be surprised by Ukraine attacking the best defense, especially without isolating the ammo supplies. I mean now we see some effort at that- deep strikes into ammo reserves in Crimea, bridge attacks, etc. Clearly up to now russia ammo reserves continue to be sufficient to be deadly. It doesn't help anyone to underestimate the enemy much as Trent telenko does- according to him russian logistics would have been over by now and russia would not have any ammo. I should have added that many of the earliest storm shadow strikes were against command positions, not ammo.
Command positions make sense. Ukraine wanted to thin out the leadership. They know that Russia' has no NCO corps and their military actively discourages anyone taking initiative. So if the officers are gone, the mobiks will just sit there for the most part.
When Ukraine started pushing in the south was when Russia started moving up more supply to be at hand for the defense. That was the time to hit the ammo depots because they were full at that point. The Ukrainians probably had good scouting on locations and supply levels at every ammunition depot in the theater. They have waited until the depots were full before hitting them. That inflicts the most damage.
There are many complaints coming from the frontlines all over Ukraine that Russian troops aren't getting ammunition, they aren't getting food, and they aren't getting paid. It sounds to me like Russian transport logistics are having a lot of trouble.
Armies do sometimes collapse, but that's an unpredictable event. Sometimes an army will hold together way past the point most people would have predicted an end, and other armies fell apart quickly.
Russia is behaving like an army that does have a lot of problems. So far they have held it together, but things back home are getting wobbly and their supply system is a mess.