Blinken and Lavrov Meet as Tensions Mount Over Ukraine

Moves by President Vladimir V. Putin of Russia to mass about 100,000 troops near the borders with Ukraine have prompted urgent diplomacy aimed at staving off a potential new war in Europe. On Wednesday, President Biden said that he expected the Russian leader to send troops over the border, but added: “I think he will pay a serious and dear price for it.”

Here are some key questions surrounding the crisis:

Why is Putin threatening war with Ukraine?

Most diplomats and experts aren’t entirely sure. Even Mr. Putin’s top advisers may not know how seriously he is considering an invasion, a murkiness that allows the Russian leader to declare the confrontation a success in multiple scenarios.

“The expert opinion that I can authoritatively declare is: Who the heck knows?” Fyodor Lukyanov, a Russian foreign-policy analyst who advises the Kremlin, said recently.

Why is the U.S. so alarmed?

A successful invasion would establish Russia as a dominant, expansionist power in Eastern Europe. It would make other democracies (like Taiwan) worry that they could be vulnerable to takeover by nearby authoritarian countries (like China).

What does Putin say his rationale is?

In the collapse of the Soviet Union, Ukraine was arguably the most painful loss for Moscow. It was the most populous former Soviet republic to form its own country apart from Russia. The two now share a 1,200-mile border, and Putin often cites their deep cultural ties.

But Ukraine has drifted toward the West in recent years. The United States and its allies have increased military aid to Ukraine and also said — albeit vaguely — that Ukraine will one day join NATO.

Russia has demanded that NATO pledge never to admit Ukraine and to pull back its troops in Eastern Europe (effectively to where they were in the late 1990s). President Biden said this week that Ukraine was unlikely to join NATO “in the near term,” but ruled out the idea of removing NATO troops from Eastern Europe.

What isn’t Putin saying?

Some observers believe that the troop buildup is a mixture of bluff and distraction, arguing that a full-scale invasion of Ukraine could be bloody and expensive, potentially damaging Russia’s economy and Putin’s political standing.

So far, Putin does not appear to be preparing Russians to go to war. Russia’s deputy foreign minister continued this pattern, saying on Wednesday, “We will not attack, strike, invade, quote unquote, whatever, Ukraine.”

But by making an invasion seem possible, experts argue that Putin can try to win other concessions, such as a freer hand in Eastern Europe.

So the risk of war is low?

Not necessarily. Even skeptics acknowledge that it is possible, given the lack of transparency about Mr. Putin’s thinking.

A few analysts, like Melinda Haring of the Atlantic Council, believe that war is likely: Putin has lost patience with Ukraine, she has written, and believes the United States would not go to war over it. President Biden said this week that a “minor incursion” would not necessarily pull the United States into the fight.