I don't know how it was in the rest of Eastern Europe, but for instance the East German government was much more 'conservative' than Gorbatchev and heavily opposed to perestroika/glasnost. If Gorbatchev wouldn't have left Honecker hanging dry, Honecker would have welcomed the Soviet tanks against his own people.
You don't need to be able to compete with the US military technology to kill unarmed protesters. T-54s will do just fine.
The thing is, the tanks would have to get there. Getting a tank 1000 km past at least 3 unfriendly borders is an enormous logistics issue, and a major resource drain - resources that simply did not exist, not even talking about the human resources.
And you're discounting the strength of millions of super-angry people too much. They would destroy the few tanks with rocks (or molotovs, as illustrated in Ukraine) if they had to.
You've probably been born after the Cold War, but just to put things into perspective, the Soviet Union had half a million troops and dozens of tank divisions already stationed in East Germany, they wouldn't have to fight their way through Poland. And it probably wasn't all that different in the other countries along the Iron Curtain.
Same thing in Czechoslovakia, but ultimately the KGB, StB and the local communist party government decided they would not be able to win, only prolong it a little. IIRC from my history classes their projection was 'less than a year and with enormous human costs on both sides, and productivity going to zero due to the whole-population rebellion' - which leads me to the conclusion that they would need significant resources delivered from USSR. Wasn't it similar in DDR?
(A lot of the StB guys decided to simply take advantage of the coming economical transformation and subsequently stole a lot of corporations and other stuff from the general public)
But that's the whole point isn't it? Would the local governments have held back if they would have been pressured by an aggressive Soviet overlord to start a civil war on their own soil? I guess the exact details why the East German army didn't leave their barracks are still not really clarified (e.g. was it incompetence, insubordination, passive resistance, unwilligness to have the blood of their own people on their hands?), at least the last point wouldn't be an issue for Soviet soldiers stationed in East Germany if they had received orders to crush the protests. But apparently they didn't receive such orders and I think the silence out of Moscow was the main reason why the East German government remained passive too.
What good is starting a civil war you can't win and in which you will last less than a year and end up dead?
My point is, the party/StB/KGB calculated (at least in Czechoslovakia - there are their own meeting notes about it) they wouldn't be able to win, and so decided they would rather steal some stuff than destroy it (or let the rebels destroy it). If they wanted to win by force - and initially they wanted to, until they understood the scale of the rebellion - they would need much bigger forces, but that was impossible to arrange, and not for lack of willingness.
They actually deployed the army (both CzSk and Soviet troops) and police, but the rebelling masses were way too overwhelming and they chickened out - there are videos of them going/rolling tanks backwards away from the enormous masses of people (easily hundreds per one troop, not even possible to kill them with your Kalashnikov). If they fired the tank, they wouldn't last 5 minutes and their death would've been nasty. What changed from 1968 in CzSk and from the situation in China was the scale of the rebellion - in 1968 only tens of thousands of people protested, in 1989 it was millions, and each incident (not like there weren't any) caused much more people to rebel instead of suppressing it.
And there was no silence out of Moscow. There are records of USSR-CzSk phone calls about this, and it was definitely not silence nor "we won't do it because it's bad" but "we can't do it because we're out of money, you're on your own BUT DO SOMETHING OR ELSE" (the CzSk side was asking for air support and so on). I assure you that if they went with force all the communist party members, StB/KGB agents and Russian troops would've been hanged afterwards - so the only remaining option was to let it happen and this way they all survived and some even thrived (like for example Andrej Babiš).
Gorbachev's "democratic-communist" (hah, what an oxymoron) Soviet Union could've never worked without the satellite states which supplied most high technology, a lot of important natural resources, etc with dictated prices USSR could afford, so I really don't think he'd just let it go if he had any other option. Certainly the phone calls didn't sound like they were happy about it or that it was the plan all along.
Overall, I don't buy the Gorbachev==good view. Perhaps he let the fall in DDR happen, but probably only because he was busy trying to keep other parts of the empire such as Hungary and the Baltics. He might've been better than the previous leaders, sure - but who isn't better than Stalin and the party? He was still an imperialist even to the modern times, and wanted to force communism (and all the associated baggage) down the throats of his subjects even though the people were demanding the end of planned economy. That makes him bad in my eyes regardless of whether he decided to let the fall happen or not, anyways. Certainly nobody to be fond of, and probably just a case of being at the right time at the right place - it's not like he could've said anything else than he said without being thrown out of the window.
Transport them? What are you talking about? The Soviets had bases all over the place in Eastern Europe.
The case being discussed here, Eastern Germany, was just behind the iron curtain, remember? Soviet troops were at ~300 locations on the GDR territory, ~50 airfields, over 300,000 soldiers, over 4,000 tanks.
The stationed troops and machines were not nearly enough to handle the situation, see my sibling comments. You can't suppress protests of several millions with 300k not-so-willing troops and 5000 not-so-good tanks (the Czechoslovaks manufactured their own tanks because of how bad the Soviet manufacturing was).
For one thing, the problem is your tanks and troops have to be ready all around the country - the protesting people are moving across the state quickly. One day there's a protest in Prague, second day it's in Brno - but you can't move your 300k troops and 5000 tanks from Prague to Brno in a day. And then the next day it's Ostrava and you have to do it again. Then an incident happens and that provokes a 10x bigger protest in Prague, Brno and Ostrava at the same time. That's impossible. You need much, much more troops and tanks to handle this scale of rebellion - and the requested air support that never came. And your tanks will never make people go back to work, anyways.
> The stationed troops and machines were not nearly enough to handle the situation, see my sibling comments. You can't suppress protests of several millions with 300k not-so-willing troops and 5000 not-so-good tanks
I don't know how old you are or where you were at the time. I was there. In the GDR, in East Berlin. On the streets. And I can tell you, a few tanks and troops getting their guns out would have made major impressions on people.
It's not just a numbers game. You are greatly oversimplifying history here. Quite naively so, I might add.
It's a great achievement of history that Gorbachev made the Soviets keep their feet still and among many eastern Germans it's regarded as quite the miracle that this whole episode went down non-violently. Look around in the world in the last decades. This was the major exception, and Gorbachev was central to that.
Also, let's get the picture of the situation straight. He didn't just passively sit bunkered in in Moscow, letting things happen. He actively went out to meet leaders of other involved powers, including the German chancellor and foreign minister, Kohl and Genscher, which he outlived by a few years.
Well, OK - I accept your opinion about GDR. But there are still the other states, and Gorbachev somehow forgot to save these too. I don't understand what makes him so good in light of the events in these other places. Isn't it interesting that only Germans are protective of him? You never hear such opinion in former Czechoslovakia. I never heard someone from Poland or Hungary talk about Gorbachev positively - neutral at best, and very unusually.
But Poland, Hungary, etc - they were not divided at least. It was a much bigger deal for Germany than for them. Also, the echo of WWII plays some role here I guess. Germany and other East European countries are in different positions here.
To expand, it seems to me like he worked to be friendly with the largest European economy while continuing to stomp on the smaller ones who didn't have their West part to look after them. Manipulative and calculating, definitely not good. Thank your West German friends, not Gorbachev.
You don't need to be able to compete with the US military technology to kill unarmed protesters. T-54s will do just fine.