It's hard to know "what could have been," but what aspect of current life/ society/ the world wouldn't be significantly different today?
It was culmination of long process started by Nixon in 1972. Shanghai Communique pledged to work toward the full diplomatic relations. Ford and Carter followed trough the process.
Taiwan really didn't matter during the Cold War. Relations with China was strategic move to help create distance between Soviet Union and China.
The US had plenty of time to safely pivot to a different position regarding China/Taiwan (e.g. letting Taiwan get nukes in the 70s-80s; Shifting diplomatic position and recognizing Taiwan right after the Cold War was over; Not allowing Globalization to go so far in the 90s-00s). If the US didn't take that option, one can blame successor presidents rather than Nixon.
Giving Taiwan nukes would’ve been a casus belli situation.
This would’ve caused China to invade. Damned be the consequences or cost of lives.
The same is true today. If America arms Taiwan with too many advanced weapons, then it will also trigger a casus belli event on China’s part.
If America couldn’t beat China in North Korea in 1950, when the Chinese were literally fighting with bows and arrows, and America had air power and carpet bombing, then do you really think America can beat China in 2021? Or 2030? Or 2050?
At that time, the PLA was in a poor state. China simply did not have the ability to invade Taiwan or even get air superiority. They'd have lost, badly, so long as the US kept supporting Taiwan, quite likely the US wouldn't have had to even get involved directly. That's a consequence the CCP can't afford, they'd have had to get used to nukes. Of course, now the balance has changed and that's not practical.
E: You're assuming China always gets stronger over time. Recently that's true, but at the time China was picking itself up from the Cultural Revolution, while the US was rearming after Vietnam. US had a far bigger advantage in 1975-1985 over China than in 1950. This scenario would have also required the PLA to make an air or amphibious assault without (at the time) sufficient airplanes or boats, while 1950 was just a land assault.
A war with Taiwan is a completely different story.
But of course, you're correct.
And Carter (and Nixon and Ford) obviously didn't have the foresight to realize the ultimate impact of the process/decision. Yet they would have been aware it was a major, influential policy decision.
Does "starting the process" count as an ultimately-weighty-political-decision?
Along the lines of "Deciding to drop the bomb on Hiroshima," if you want to count that as a decision by one person. Of course it was also just one node of a decision tree that was a long, complicated chain-of-events.
It was probably Kissinger with rosy “divide and conquer” thinking given Moscow & Beijing had a fall out.
If Nixon hadn't started the process, if carter hadn't recognize the communist government of China.
- Offshoring/globalization may not have been the boom it is today, due to the lack of a major source of cheap/obedient labor force. In the 70s offshoring occured in Japan, Taiwan, South Korea and others SE Asia countries but they didn't have enough cheap labors to continue. American companies would have been timid to shift operations to Indonesia and India when they lacked severe infrastructure, with no totalitarian government to enforce cheap labor.
- As a corollary, GE/Intel would not not have shed all its capabilities to Asia, and be greatly diminished today.
- Wall street might not have been able to push companies to greatly shed cost and ship capabilities overseas due to national security issues. As a result, US unions would have been intact somewhat and the jobs would not have been shipped to China. Flyover states would have enjoyed greater strength as they did in the 60s and 70s.
- the great crash of 2008 would not have happened (Chinese entry into WTO greatly reduced manual jobs in US and Europe, crashing both economies)
- Trump would not have been elected. Trump was a reaction to much jobs lost and much sufferings in flyover states caused by China.
- Coronavirus spread around the world and all the deaths that occurred may not have happened (China would have been still a closed off country, not unlike what Xi Jing Ping is trying to do today). No mass flights out of Wuhan or Beijing.
The Chinese would’ve come online, sooner or later. The WTO sped up the process of course, but China’s technological ascendancy was inevitable.
The other theory is that if China was denied entry into the WTO, then they would’ve just created their own international trading agreement. And in 2020, they did just that, and called it the RCEP.
Besides, without China, then your iPhone would’ve probably never been created. Apple would’ve never made enough money from the iPod, to justify further investment into the iPhone. China and the iPhone, really are symbiotic. Instead, we might all be living in a Blackberry world.
I dispute that anything is inevitable - China was an economic and scientific mess in the 80s and 90s, thanks to the Cultural Revolution and Communist anti-truth thought control ideology.
The US and our democratic allies had a fleeting opportunity in the 90s to collectively pressure China into making a grand bargain, where in return for permanent access to Western markets, they enact major democratic and human rights reforms - multiple political parties allowed, separation of powers, checks and balances, independent judiciary, military serves the national constitution rather than a specific political party, etc.
This is what should have happened, but in Wall St. and corporate America's rush to cash in on cheap labor and a potentially large new market, we replaced that grand bargain with wishful thinking and a rose-tinted predictions of an authoritarian regime that just a few years earlier in 1989 violently crushed a nascent effort at Democracy.
This was likely the most costly strategic mistake in US history. We spent 50yrs fighting a cold war to push back authoritarianism, and won, only to snatch defeat from the jaws of victory in the 90s due to short-term greed. Now we'll have to fight that cold war all over again this century, against a much more formidable adversary that has been able to learn how to meld state authoritarianism with effective economic development and Orwellian technological thought control.