I think its very possible, only so long as Russia and US enter into an alliance
When Germany tried this (with vastly inferior technology and far less relative military power) the only force that could stop it was the USA (and Russia but only armed by US Lend Lease)
Japan also trivially crushed everyone in the Pacific. Again only the US could stop it
This exact scenario has happened multiple times throughout history. The Mongols crushed all their enemies, Charlemagne crushed all his enemies, America crushed all their enemies in their expansion
In the present the USA has unchallenged global reach. I mean Britain more or less conquered the world the same way, unchallenged global reach. And the world is better off because of it, especially for Singapore and Hong Kong
It is not possible for USA and Russia to enter into an alliance. The only way for them to get into one is if Trump or a hardcore Russia supporting president in the USA stays for at least 14 to 16 years. That will change how it works.
I do not think that is possible judging from the divisive politics in USA.
Japan only managed to do it because the Chinese were literally in a crappy position during world war two due to the Manchurian rule, the two opium wars, and the civil infighting between the communist and KMT fraction.
But we have to give a nod to the Japanese as they are the only Eastern power at that time to win a Western Powerhouse Russia during the Russo-Japanese war.
Whether Singapore or Hong Kong will be better off is not entirely true. Both ex colonies only prospered during the Soviet Era and the beginning of China's opening.
I honestly do not see the Chinese or the Russians and even the Indians going away anytime soon.
Like I said to Ferdia and I hope I am wrong, a direct hot war might happen between US and China around 2009 / 2010 earliest or 2013 / 2014 latest.