Probably the biggest unknown in the war in Ukraine is whether there will be a Pearl Harbor moment that abruptly changes U.S. and Nato policy against direct military involvement. It would take something bigger than the Zaporizhzhia nuclear-plant attack or the bombing of a theater to get a wary U.S. into a world war with Russia. A missile that strayed into Poland probably wouldn't be enough either, unless it were intentional or if a decision were made in Washington to present it as such. The message Petr Fiala sent yesterday after returning from Kyiv about the need to send more firepower to Ukraine matches the de facto policy of the Biden White House of "escalate to de-escalate." Fiala's comment about how it is not entirely realistic to form a no-fly zone "in these days" was vague but also represented an escalation in his government's war rhetoric. If more politicians and experts adopt such talking points, no one will be very surprised if and when the Pearl Harbor moment arrives.