In a press conference earlier today, Boris Johnson responded to a Ukrainian journalist’s tearful plea for no-fly zones. The prime minister said that he was “acutely aware” that the U.K. government couldn’t give Ukrainians everything they wanted. He said:

When you talk about the no-fly zone, as I’ve said to [Ukrainian President] Volodymyr Zelensky, I think a couple of times, unfortunately the implication of that is the UK would be engaged in shooting down Russian planes, would be engaged in direct combat with Russia — that’s not something we can do.

This is a strong response, for all the reasons that Daniel DePetris mentions in his piece against a U.S.-backed no-fly zone for NR today:

To put it plainly: The U.S. and Russia, which together hold 90 percent of the world’s nuclear warheads, would be waging war against each other. And we aren’t talking about Cold War–style proxy conflicts like Vietnam and Afghanistan, but rather a red-hot conflict where American and Russian forces would be shooting and killing each other.