Well, there should have been a proportional level of plotting relative to the size and importance of the country then.
And there was a connection based on gegraphical proximity and historical relationships.

My impression is that the USSR was acting in a relatively predictable way militarily and was actually more honest about its intent than anyone in the West gave it credit for at the time. This seems to be the picture that is emerging now that statements can be verified.

Its' interests being primarily protecting Russia and having a sphere of interest surrounding it, protecting USSR and the socialist state they had created. Secondly it was driven by ideology which spurred it to support "liberation movements" in various countries and socialism in the third world.

The US on the other hand was a lot less predictable, driven by the objective of ruining socialism and by fluctuating financial motivations. This meant it was less predictable and more volatile. "Our enemy's enemy is our friend" which lead to it supporting some gruesome dictators and crazy radicals.... the results of which we can see today. It also lead to it spying and plotting on countries for no other reason than economic gain.

I have nothing against critisizing the USSR for the many things it did wrong, but I think the shooting down of this plane was an unfortunate mistake in a tense military situation. No conspiracy and no covering up that involved any survivors.