Well, that was quite a week to take off: The state said I-85 would re-open in about two months, Jon Ossoff revealed almost all of his financial support comes from well beyond the district he hopes to represent in Congress, Senate Republicans pulled a Harry Reid and killed the filibuster for Supreme Court nominees, and Democrats learned Syria still has chemical weapons after all .

Let's start with the last of those. Those who did not buy into the Obama administration's deep self-regard had long been skeptical of the deal brokered with Russia to remove Syria's chemical-weapons stockpile. This deal came about back when Democrats were the ones who thought Russia was a potential ally, or at least a nation with which we might find common cause when dealing with international problems. Obama administration figures continued to tout the deal as a success even as the Assad regime continued to weaponize chemicals such as chlorine against the Syrian people. (The technicality cited by defenders of one of those administration figures, former National Security Adviser Susan Rice -- that she was talking only about Syria's "known" stockpile -- only underscores just how incomplete and ineffective the Russian-led effort was bound to be.)

So it should hardly have come as a surprise last week when reports emerged that the Syrian government had once again bombed civilians with some kind of poisonous gas. Nor should it have been surprising that Russia, as it has time and again, echoed the regime's denial of using chemical weapons.

What did surprise was the reaction from President Trump.

Four years ago, Trump publicly and repeatedly cautioned President Obama against striking the Assad regime for crossing Obama's "red line" by using chemical weapons. Now in the White House himself, Trump apparently was so moved by images of suffering Syrian children that he ordered a cruise-missile strike against the regime-controlled air field from which the chemical attacks were said to have been launched.

And, as we did four years ago when Obama proposed retaliatory action against Syria, Americans are left wondering whether Trump's action signals any kind of broader commitment to intervention in Syria or a relatively tame, one-time, symbolic act. In raising that question now, a number of commentators are also asking what, exactly, are the guiding principles behind the Trump foreign policy.

But the response to Assad's chemical-weapons use fits neatly with a concept of Trump's foreign policy that I've held for a while now, and which I'll try to explain. I call it the "weaving car" approach to foreign policy.

We've all been on the highway and come upon a motorist who seems incapable of maintaining his lane. We wonder: Is he drunk? Distracted? Suffering a medical emergency? Just plain bad at driving? But ultimately most of us probably decide not to get close enough to answer the question; instead we give the weaving car a wide berth and steer clear of it. For the one thing that's clear is the car poses a danger in its failure to follow the rules of the road and to behave predictably.

For decades now, the goal of our foreign policy has been to ensure as much predictability as possible. We try to signal our own intentions and to encourage the same from allies and foes alike. (I'm speaking here of strategy, not tactics.) Order has been the goal. That includes the order established by military alliances such as NATO to deter bad actors, as well as the order built by trade agreements to foster cooperation even with countries such as China that aren't considered our allies. Perfect predictability was of course never feasible, but the theory was that, by eliminating as much happenstance as possible, we were better placed to deal with those unforeseen problems that did crop up.

Those notions of order are obviously rejected by terrorists, who value unpredictability because it helps level the battlefield for them against the world's leading powers. But lately, the wisdom of seeking order and predictability through international institutions, and pursuing one's national interests within those frameworks, has been questioned as well by populists in the West. That applies to Brexit, obviously, but also much of what Trump had to say about foreign policy as a candidate. We might describe the main unifying theme for his thoughts on foreign policy as: America first, no matter how many apple carts must be upset -- among friends or foes.

The problem is that, while order was itself seen as a national interest of the world's only superpower, this upsetting of order lacks a sufficiently clear goal. Despite its apparently appealing simplicity, "America first" is not an organizing principle. Actions that seem to put "America first" today may be harmful to our national interest in the long run. Threatening to walk away from NATO because some countries haven't been spending sufficiently on defense is one example. There may also be situations where yielding on a relatively small matter of national interest brings us allies, or helps avoid conflicts, on more important matters. The adage that countries don't go to war with their trading partners comes to mind.

In the short run, an erratic America may make some bad actors think twice about coming too close to us. In the long and even medium term, however, this approach is more likely to make our allies wary of us and our enemies tempted to try to use our whimsy to their advantage. Neither is desirable.