For months, U.S. officials have privately conveyed their concerns over the course of the war in Ukraine. In public, they stressed their enduring commitment to help Kyiv resist Russia’s brutal invasion and vowed to support its efforts as long as it takes. But in more candid discussions, with reporters and directly with Ukrainians, they pointed to a tougher reality: A total military victory for Ukraine seemed impossible; the military-industrial base in Western countries required to sustain the flow of foreign munitions and arms to the front was under severe strain; and, at some point, the support of Western publics, especially Americans, would wane, and the spigot gushing tens of billions of dollars in aid to Ukraine would get turned off.