We do have a complicate feeling regarding this issue..
If they did not do it, China may be like USSR countries without the high economy growth but political chaos.
Yet in 1980s, people had very high expectancy and support on the CCP government, wishing it to lead China out of poverty and political chaos.
Economy and political reform goes well, supported by people of all class.
Yet after Tiananmen square issue, the political reform was ceased.
CCP focus only on economy only.
Now people only knows money...
Nah, the political reform is an ongoing process. It still continues today. Heck, about 20% of the news from CCTV-1 everyday is on internal reforms and issues.
However, what June 4th did was the end of radical revolutions. Ever since 1949, China has been going through rapid social and political changes. From the initial five year plans in the 50s and 60s, to the culture revolution from mid-60s to 70s, to economic reforms from mid-70s to 80s. China has been changing at a break neck pace. June the 4th is the when the Chinese leaders finally said that "Okay, we are going way too fast, time to slow down and consolidate". Indeed, the entire 90s period is a time of consolidation, both in political policy and economic reform.
The event at Tiananmen square itself is actually not that complicated at all. It goes something like this:
1. Prelude: rapid economic development in the 80s created a wealth divide among the Chinese population. While it is nothing noteworthy by American or Indian standards, the Chinese who had much less wealth gap previously, was surprised by it. Mind set changes and coupled with the fact that the associate structure of governance did not develop fast enough to keep up with the economic development, corruption and other issues become serious. (Again, not at a level that is noteworthy comparing to US and India standard, but again that was kinda new for the Chinese)
2. Build-up: In typical fashion of that time, people gets into a revolutionary high and attempted to solve the problem via rapid, drastic change in political structure. Not realizing problem with corruption and wealth inequality is a much more long term problem than issues like foreign invasion, hunger, lack of infrastructure or disease. The latter problems had been the main issue for PRC. These issues are "simple", because they have a clear solution and an end in sight, you just need to get from point A to point B in a straight forward manner and overcome the obstacles in the way. The former, like corruption and wealth inequality, are like much less straight forward and isn't something that can be solved through a large drastic change. However, they say hindsight is 20/20. Most of the students at that time, as typical of young people with little experience in politics or world in general, do not have the slightest idea. To be fair, a lot of people in Chinese government itself doesn't understand this either. In hindsight it make sense. A lot of these people were originally down to earth farmers and workers, not from political families that have been bathed in court intrigues for generations.
So, the students were ferried by the Chinese government itself to Beijing. To listen to student's ideas for change.
3. Stalemate: The students were enthusiastic. Why would they? They were young and idealist. They absorb information much faster than the older generation and not boggled down by tradition. Of course, this is a very flattering way of describing them. A more realistic description would they had good intention and some idea on what is right and what is wrong, but they are inexperience, gullible and can't see through the complex maze of politic even with a guide and a map. They did provide a lot of ideas, but most of them simply makes the older and more experienced adults frown and goes ""Were you drunk when you come up with this? Have you thought about the consequences?" Some of the especially stupid and hilarious idea include giving a group of student about 20 year old political power and make them the equal to CCP. To put in perspective, Clinton was one of the youngest president of United States because he was
47. Kim Jong Un, who inherited the position in a dynastic North Korea was
28 when he took office. So when these students about 2/3 of the age of a Kim Jong Un proposed that they took power of China, the Chinese government officials, who were thankfully sane, shotdown the idea as ridicules.
Of course, this was after the Chinese government had agreed on various reforms for five different times in the negotiation, but you know young people, they can get pretty greedy if they can have their way. So each time they will increase the demand, until finally they reached the point of openly demanding power and Chinese government have to shot down their demand.
4. Escalate: Now, if things died down at this point, it will be a rather quiet event. Students will go home with tail between their legs and many decades later when they recall this, they gonna have a laugh about the naivete of their youth. Chinese government will probably implement some of the reforms, some will succeed and some may fail. Everyone goes on with their business. However, in that particular event, something else is at work. Many years after the events, people begin to see some of the details as unusual and strange. For example, the supposed student leaders were out of the country by the end of the day and across the ocean within the ocean. In 1989, that kind of speed was simply ridicules, couldn't be done without a lot of pre-planning. This means these student leaders expected to run out of the country in a hurry, despite the fact there was simply no precedence on how the Chinese government would react.
Nowadays, especially after observing the dissolution of USSR and the more recent Arabic Springs, it is generally agreed that the groups backing the student "leaders" have links with foreign intelligence services, especially the intelligence services that were involved with the dissolution of USSR. Similar methods of operation has also been observed in numerous conflicts in the followings decades, such as the Arabic spring, revolution in Egypt and many other similar events. A collective term for these type of maneuver is called color revolution. It describes a method of systemically disrupting another sovereign nation through none direct military and economic means. In color revolutions, the original government of the nation is overthrown through protests that starts out peaceful and "somehow" took a violent turn. It will then span out of control. Should the original government stand firm, a civil war may erupt and the opposition would sudden get weapons and other resources from their backer.
In 1989, at Beijing, this precisely what happened. Someone somehow fired a shot, then someone claimed to be injured and violence broke out. Now, should this kinda of event occurs in US, there is a standard set of procedure for it. The police will fire tear gas, pepper spray and rubber bullet. The armored vehicles will be used to disperse the crowd and arrest a large group of people indiscriminately and sort them out latter. Then the news agencies are instructed to run damage control. A good method is holding lengthy debates on technicalities. The result of the debate itself is not the goal, the idea is that to drown the event through both time and sheer volume of information. A few weeks down the road, people would have forgotten a great deal about it and everyone can get back to their lives. We have seen similar methods in the recent Ferguson and Baltimore riots. However, unlike the Americans, which had plenty of experience with this kind of problem, the Chinese government at 1989 is ill prepared to deal with it. Hence, they called in the army. The move is effective, but very crude. It is equivalent of performing surgery with a large butcher knife instead a precise instrument like a scalpel.
5 Aftermath: There are plenty of negative impacts of the event and I don't really need to list them out one by one, but suffice to say while the Chinese government made the right call at the time, their method of implementation could have been a lot better. Make no mistake, color revolution must be stopped in its developing stage, though one should refrain from the big guns when a small, precise strike will do.