Back in November of 1987, the US and Russia signed a missile treaty. Basically....short-range missiles were OK, and long-range missiles were bad.
New missile programs came and went. So in the past couple of years, the Russians came onto this new program (SSC-8)....a cruise missile, which they said only went about 480 kilometers (300 miles). The US monitored testing....no one says how but they did. In their mind, the cruise missile is capable of carrying nukes and going up to 2000 kilometers (1,200 miles).
After a number of months of talking about this....President Trump finally said that the 1987 treaty is dissolved (will take six months for this to occur).
Naturally, this has hyped up the Europeans a lot (especially the Germans). Russia? They've warned the US about bringing in medium-range cruise missiles to off-set this. So they are chatting about bringing in missiles to Cuba or Venezuela to play this game out.
Trump's game-plan? Unknown. But this might be an occasion where he tells the NATO folks (in particular the Germans) that he has zero intention of bringing in more missiles to Europe, and that if they have a serious worry.....maybe they should take care of it themselves.
You see, the chief method of Russia making Oligarchs wealthy and rich.....is by oil and natural gas sales to Europe. I don't think any Russian Oligarch or billionaire has any desire to mess up this situation.
So this is all fake 'worry'? More or less. They will spend hours and hours trying to do public TV displays about Trump screwing up. Well....he's actually telling Germany and the others....it's your business to protect yourself, and we won't necessarily be paying for it or helping you.
As for the SSC-8? Somewhere in the next year or two, I expect the Russians to conduct some test and demonstrate to the Europeans that it can go 2000 to 3000 kilometers. NATO will try to entice Trump to come into the picture, and he'll tell them that it's their situation to resolve.