https://www.rferl.org/a/lithuania-soviet-crackdown-1991-krem...
https://www.rferl.org/a/lithuania-soviet-crackdown-1991-krem...
You seem to comment to better inform readers, yet your comment distorts the truth.
Even the article you linked talks about Lithuania declaring independence from the USSR, not asking for democratic reforms.
Despite what your article says, if you read the story on Wikipedia, Lithuania did in fact unilaterally declare independence from the USSR in March 1990.
Just as an example, check what Spain did in 2017 when Catalonia tried to declare independence after a popular vote. If Catalonians decided to resist, there is no doubt that the Spanish state would have used violence to suppress them. Try to imagine what the USA would do if any of its states tried to declare independence.
It's an intriguing historical question what would have happened if Fort Sumter hadn't been attacked. Would the Union have eventually made the first move? Would peaceful negotiations have eventually resulted in some stronger guarantee in the continuance of slavery and an end to secession? Would the Union have eventually dissolved amicably?
Going by what happened during the Nullification Crisis, the answer is likely a "Yes".