Hard question. We still don't really know the deal between Trump and Putin. There is a lot that is suggestive, but nothing conclusive, and the latest round is compatible with both the story that Trump is free of influence, and the story that he is being blackmailed.
Suppose Putin has nothing on Trump. This is pretty much how things would play out. If Trump isn't being blackmailed, then everything we have seen between them recently is basically because Trump is just a dictator-worshipper. He idolizes Putin personally because Putin does what Trump wishes he could do. But, in the end, Trump will do what is in his own best interests, and without any control from Putin, that means flapping about whichever way the wind blows. Congress passes a bill? Fine. Fuck Putin. Too bad, Vlady. OOOOOH! You kicked out some diplomats! I'm SOOOO SCARED!
Wait. You mean North Korea is launching ICBMs? Fuck. OK, that's scary. Um... I thought everyone was supposed to be too scared of our bigly president to pull anything like that. You mean that doesn't work? Damn. So much for that...*
Anyway, back to Russia. It is easy to see how this sequence is compatible with the no-blackmail model. What about the Trump-is-being-blackmailed hypothesis? There, too, it is compatible. It simply requires understanding that Putin is a) smart, and b) constrained. Trump's (tiny) hands are tied here. Presidents have a lot more authority in the international arena than in the domestic arena. In matters of war, their powers are essentially unchecked, since Congress has basically abdicated all power. Yes, the Constitution says that Congress, not the President declares war, but Congress is a body consisting of 535 spineless cowards who never want to take responsibility for anything. Back when Obama was President, Assad crossed the "red line" of using chemical weapons. Apparently, hacking someone's guts out with a machete is totally cool, even when done on a mass scale (see Rwanda) but killing them with chemicals is unacceptable to this fuckin' country. OOOOH! CHEMICALS are SCAAARY! Anyway, Obama was going to do something, but then Congress said, "not without our authorization!" Obama said, "fine. Hold a vote." Congress freaked the fuck out. If they voted no, then they were voting to let Assad continue. They were being a bunch of anti-war hippy pussies. If they voted yes, they would be on the hook for any bad thing that might happen (see Iraq). So, after demanding that Obama not do anything without a vote, Congress refused to vote.
The effect of Congress taking itself out of the war powers business is to give complete power to the executive over war.
Diplomacy, though? Not so much. There, Trump's hands are tied, as Trump just learned because he entered this job thinking he knew all, but knowing precisely fuck-all. If Congress is going to impose sanctions, and pass a bipartisan law that prevents the president from loosening them, Trump can't stop them.
And Putin, being much smarter than Trump, probably knows this.
So, what if Putin has blackmail material on Trump, but simply understands that Trump can't deliver on this? There's no reason to expose your pawn if he is doing everything he can, but just doesn't have the power to get it done, but Putin would have to respond, diplomatically, or look weak on the international front.
Really, then, what just happened is compatible with either story. Is Trump being blackmailed? We still don't know.
If I had to guess at this point, here's what I would speculate. All it would take to have something on Trump is the following. Find some low-level person in an accounting office to get some of his financial records. Trump would pay anything to keep those secret. But, as I have written many times before, if you do have blackmail material on someone, as soon as you make it hostile, that person looks for ways to get out from under your thumb. Trump is positively disposed towards Putin by general inclination, so Putin has no reason to use whatever he has, but I'd bet he has something. Trump is just too crooked, and too stupid about his corruption for him to keep everything secret from Putin and the FSB. But, you don't make a blackmail target your enemy unless you have to do so. You keep that in your back pocket as a last resort, particularly when Trump is so obviously enamored of Putin. He just couldn't deliver, with Congress breathing down his neck. He may not be able to deliver for a while. That could spell trouble for him. If he is being blackmailed, Putin may not be very patient.
Of course, maybe Putin doesn't have anything. We still don't really know, and even Mueller won't find that out. Mueller will probably find out if Trump has active business interests in Russia, which is itself important, but he can't get access to the FSB. This is still a total mess.
Yes, we are still stuck with a mystery of whether or not our President is controlled by Russia. We really, seriously have to consider this. This is our world.
*I'll revisit this later in reference to a series I did a while back called "Political science and craziness."