Not since the Cold War ended has the world faced the prospect of a clash between two nuclear-armed superpowers with such urgency. The United States has imposed economic sanctions on Russia, sent troops to help train Ukrainian forces and increased military exercises with NATO allies in Eastern Europe. But Washington has not yet supplied Ukraine with weapons or ammunition — an apparent effort to avoid a proxy war with Russia and limit the damage that would be inflicted on American allies should Moscow take retaliatory action against them.

In the air, the US has a significant advantage with far more bases and fighter jets. On the ground, Russia has the edge with more tanks and artillery. But at sea, the US has a clear advantage with more destroyers and aircraft carriers. The US also spends more on its military, about 612 billion versus 77 billion for Russia.

The presidential hopeful and former vice president Mike Pence, a Republican, has called for supplying Ukraine with whatever assistance is necessary to turn back the Russian invasion. He said on the Hugh Hewitt Show that Putin’s war in Ukraine is “evil,” adding that he believes the conflict is being provoked by internal divisions in Russia.

The United States and Russia have different paths to military might, but both have formidable conventional and nuclear weapons capabilities. Americans are more likely than other Western countries to have a very unfavorable view of Russia. Democrats and Democratic-leaning independents are 5 points more likely than Republicans and Republican leaners to hold that view.