How will UK Prime Minister Boris Johnson deliver Brexit?

Not well, not on time, and probably means an early election instead of delivering Brexit, which may mean that he's in a stronger position to deliver Brexit after that election is through but also may mean he loses power and Corbyn is the next PM - much worse than even Brexit.

Should the US tax French wine?

No, no, no. In part because you need to focus on the Chinese. If you want to actually squeeze China, which is a worthy thing to do on trade and technology, you need American allies. Stage your concerns. Though I have to say, I consider Napa wine to be eminently more quaffable than French wine so it's not a personal thing.

Will the US quit the nuclear test ban treaty?

I don't think so. The Russians are saying that we're going to but that's just following off the Americans pulling out of the Intermediate Nuclear Forces Treaty. I don't think it's going to happen but the Russians are not even in breach of it. They were in breach. They are in breach of INF and that is unfortunate because it's one more piece of the nuclear deterrence puzzle that we are losing.