In my game, Poland's my only ally (that isn't a vassal).
I decided to pick up my old Russian game (after a good week long break, i.e. Just Cause 2

), and holy crap did things go in my favor.
As you can see, I've moved into central asia and finally made a push against the Ottomans.
Due to Westernization I've been able to catch up to the rest of the world, including the Ottomans. I due to my capture of Central Asia, my manpower has been on the increase. So finally, in 1606, I had an army larger than the Ottomans and I was at the same tech level. And so, I declared war on Sibir, which also brought Khiva, Chagatai, and Khzak in along with the Ottomans. Everyone but the Ottomans were easy to handle.
The Ottomans took some really intricate strategy, due to to the fact that we're near equal in power. So when I declared war, I did what Russia always does in those situations, I scorched the land and fled. I got three massive armies (each about 30,000 men) trapped in scorched Russia. After a month, two of them left to conquer Poland, the third stayed until I destroyed it. With Poland distracting them, I blitzed Eastern Europe and conquered everything in between me and Poland. Though this wasn't enough to warrant a treaty, so I merged all my armies and begun a massive blitz to their capitol Constantinople. Though about halfway there Sweden (Holy Roman Emperor) decides to join in on the fun. And so I was able to sign a peace treaty, and take a good 5 or 6 provinces from them. This is of course the Ottoman's first defeat since they begun their rampage, and I don't plan it to be their last.
In other news:
-Bavaria has replaced Austria as the German menace in my game
-Munster is trying to create a pseudo-Netherlands, and is succeeding.
-Scotland is still alive, and is colonizing the New World. All the yellow colonies in North America (except for the Caribbean) are Scottish.
-Though Castille is having it's own fun in S. America and Africa.