Turkey is a more important ally for Russia than is Iran, because through them they can get year-round access to the world ocean via the Bosporus, which is currently how the US projects most of its hard power (that is, though its blue-water navy). However, because of the 'cold war' in the Middle east between Iran & Saudi Arabia, they can only have either Turkey or Iran since Turkey is angling to regain leadership of the Arab Muslim world. Thus I don't buy how your alliances break down (also why is Switzerland, &c. involved?)
Russia's belligerence and its consistent policy of national sovereignty is the beginning of a nascent alliance bloc against the US global order. Russia has acted with impunity in a few theaters now, against US strategic interests, and a global 'national sovereignty' movement roping in fringe states everywhere has a real chance of gathering momentum - Putin's strategy is smart, and it's effective. The Pax Americana is coming to an end, and right now the Yanks have the worst possible commander in chief, spouting protectionist economics coupled with weird aggression (a 'pull-push' dynamic) as if American wealth weren't based upon its political dominance.
What I would expect to see is the development of a key alliance between Russia and Turkey as a bipolar global order reasserts itself, which puts China in a weird outside position (which, actually, it wouldn't mind at all). Iranian retaliation might lead to localised hostilities, but it wouldn't affect the global power dynamic too much apart from sucking American resources and attention which the Russians will take advantage of.
As far as 'World War Three', no. The nuclear arsenals have not been dismantled and so major 'hostilities' will be conducted through proxy wars, economic aggression (already happening) and subtler maneuvers like interference in domestic affairs, &c. Another global cold war, though? Sure. It's already being fought.
