Everything that is fundamental has changed, though.
While the focus of the book was Moscow's panic in the face of geopolitical decline, the Warsaw Pact was still on approximate equal footing with NATO in the early 1980s. So, in addition to the two having military forces and training built up over decades, they had similar sized populations and economies to credibly support an all out war effort beyond the first engagements.
To get something similar today would need a military conflict between the US and the EU, except in an alternate reality where the EU was as politically unified as the USSR was, and where military spending took up as much of the EU economy as it now does of the US economy.
Here is some rough context of the current (or recent past) geopolitical landscape taken from some Wikipedia & CIA World Factbook stats:
GDP | Pop | Country | Mil% | Mil$
---------------------------------------
16.3T | 507.9M | EU | 1.1%?| 179B
15.7T | 316.8M | US | 4.6% | 722B
12.4T | 1.35 B | China | 2.6% | 322B
4.71T | 1.21 B | India | 1.8% | 85B
4.78T | 126.7M | Japan | 1.0% | 48B
3.38T | 143.5M | Russia | 3.9% | 132B
2.36T | 201.0M | Brazil | 1.3% | 31B
1.76T | 118.4M | Mexico | 0.5% | 9B
It's an important point, because it gets lost all the time: the US does not face foes that offer any existential threat. There aren't any countries or groups of countries that currently threaten the survival of the United States, and there aren't any reasonable fears about loss of territorial integrity.
Even if you conceptualize terrorism into a broad movement rather than a basket of tactics and behaviors, "it" still isn't a monolith and hasn't enough political unity to control a single nation, much less one that with a manufacturing base to speak of or any technological sophistication.
Red Storm Rising requires, at the least, a foe that is politically monolithic (China not the EU), that has a technologically advanced military (maybe Russia), and a sophisticated enough economy that it could sustain a war effort beyond the first couple weeks of engagement (EU not China).