Currently, other than maybe the War in Donbas, there are no direct wars between two states.

This just isn't true. There are currently running conflicts with multiple state actors in Syria, Iraq, Afghanistan, Niger, Nigeria, Somalia, Yemen, and the Caucasus. And that's not even counting insurgencies.

More over, since World War II there have been a whole host of major international wars. Korea, Vietnam, Afghanistan, Iraq, Iran, Cambodia, India, Pakistan, Argentina, Serbia, Kosovo, Turkey, Israel, Egypt, South Africa, Somalia, Ethiopia, and Ecuador. And that's just what I can think of off the top of my head. I'm sure if you went to Wikipedia, your find a much longer list.

Now, what you may be considering is that there haven't been a whole lot of wars between major powers, or in Europe. But as Mark Mazower argues, those conflicts have really just been transferred to the third world, usually via proxy wars of one form or another.

You should check out Dark Continent, where Mazower makes that argument.