What other implausibilities are there in the book?
The NATO early attack on the WP bases and bridges before hostilities officially commenced may not have been so easy to authorize. At that point Spetsnaz cells had been found in W. Germany and neutralized. NATO actually going on the offensive was a great move on NATOs side, but I would have expected some more hesitation/resistance from European governments.
The other point are the targets of that preemptive strike. Clancy had the NATO airforces take out AEW, C3, air bases, bridges. That’s great, but they did that without knowing the Soviet plan of attack. At that point, they only knew of the Spetsnaz in W.Germany.
Put yourself in SACEURs shoes:
Would you... a) hit exactly those targets b) presume the Soviets may also go nuclear and hit nuclear, biological, chemical stockpiles/launchers too c) not attack.
Point c may also appear reasonable, bearing in mind a preemptive NATO strike could provoke an escalation to nuclear warfare from the WP, who would see their plan of conventional warfare being ruined by your strike. That is, provided you knew the Soviets would not go nuclear immediately, because if you thought they would, you should consider b.
And then put yourself into the shoes of the W. German Chancellor.
Hundreds of NATO aircraft taking off from or overflying W. German territory on their way to hit targets in the WP in a preemptive NATO strike - how many nukes do you expect the Soviets to launch at you once these planes cross the inner german border?
RSR would have been a totally different book without that car accident that revealed the Soviet Spetsnaz plan.
So if the Iceland Operation went extremely well for the Soviets, that car accident went extremely unwell for them (and was a totally random factor).