It's buggy as hell too... the whole series is... Wonderful games but they just never get around to telling you what you're supposed to be doing or why. It's especially onerous when your mission critical events don't fire
I have seen no bugs so far actually... And S2 hardly requires you to even know what you're doing.
Hammer and Sickle though I can see people having problems. But a little investigation will show you the way.
Honestly, it's not that hard to figure out.
H&S isn't just hard, it's plain unfair.
Take the start of the game after you've sneaked through the border, for example. You're standing there 4 meters in front of a firing squad and their officer has spotted you, so you can't sneak around them and running away most often results in you getting shot by one of the rifles and too paralyzed to run away further. Your only chance is a grenade (being a scout, the class that would appear to make sense for the role of "spy", you only possess one) paralyzing them and that may also fail in paralyzing all of them.
The implausability of this situation is astounding as well. Why the fuck would your guy walk up to that firing squad? Why don't you start the map like at least 100 meters away from them? You're supposed to be a spy. You're controlling the worst spy in fictional history. Worse than James "here's my real name" Bond.
I trudged in save/load fashion through about 3 such scenarios and said fuck that. This is coming from someone who breezed through S2 (without using the panzerkleins) and loved it.