Ok, about the path you describe: how can one join a military exercise without a prior green light for that? And speaking about the political integration: remember that Turkey is in nato, so it does not need more political integration than Russia had in early 2000th.

What happened is that nato realized that if Russia joins, it will loose the reason to exist (i.e. if the old enemy joins the alliance what is the need for such an alliance anymore?)

So nato bureaucrats understood that they will loose well-paying positions and rejected even initial talks.