@A_C_McGregor @cstross @Longspeak @JeremyGraeme I would guess a slightly longer timescale. Even without US support it will take Russia some time to take full control of Ukraine and be ready to move on. Ukraine did remarkably well in Putin's supposedly three day war, even before it had major arms shipments, and Europe could likely move faster than it has been. And while Russia's recent attritional tactics have been taking territory, they're slow; any attempts at maneuver warfare lead to massive equipment losses for tiny territorial gains.

Also, China is still relatively cautious about supplying Russia (and therefore incurring US sanctions). That is slowly changing, with China involved in drone development etc, but it involves their economic planning and also possibly the impact of Trump on trade.

While non-US NATO has more troops and a much bigger economy than Russia, and Putin has been reluctant to mobilise fully, if China wants a protracted proxy war it can easily achieve that.

Meanwhile China isn't ready to roll into Taiwan yet. It all comes together around the time of the following election: China will be ready to go into Taiwan, Russia will have finished with Ukraine and potentially be ready (though some analysts disagree), and Trump will try to rig the election in favor of his successor (or even himself), probably triggering a full scale civil war.

All of that is less likely if Harris wins. On the other hand if China is prepared to more openly support Russia, a major European war (further west) could well happen even with a relatively internationalist US president.