When you push the button, the car window will close, unless you deliberately stop it.

Putin seems to believe, that under Ukrainian President Volodymyr Zelenskyy, Ukraine will become a NATO member. This is unacceptable to Putin. He believes, he must stop it before it happens. He sees Ukraine, as a NATO member, an existential threat to Russia.

Putin watched with great alarm how, under Zelenskyy, Ukraine made progress integrating itself into the European Union, economically and politically, with the aim of becoming a NATO member.

Putin decided to stop it. He massed Russian troops at Ukraine’s borders, trying to intimidate Zelenskyy and force him to make a commitment that Ukraine will never join NATO.

The threats didn’t work. Putin decided to invade Ukraine, supported by his advisers, the military and even by a large segment of the Russian population.

He believed, as most Russians do, that the Ukrainians are cousins, belonging to the extended Slavik family. After all, Nikita Khrushchev, the former Soviet leader, Leonid Brezhnev, another former Soviet leader, and many other high-ranking Soviet officials were of Ukrainian descent.

Putin and his military advisers believed Russian troops would reach and encircle Kyiv, the capital city of Ukraine, in days, and Zelenskyy and his government would flee, choosing exile. And the Ukrainian population would gladly return into the arms of Mother Russia.

Putin and his advisers have grossly miscalculated. Ukraine, since the break-up of the Soviet Union, has developed, with fits and spurts, into a functioning democracy, with a desire to be part of a prosperous Western Europe.

Putin has realized that an economically thriving Ukraine, a functioning democracy, Zelenskyy, as president, famous for fighting corruption, would be a mortal danger to his autocratic, “kleptocratic” regime.

He ordered the Russian military to gain the upper hand in Ukraine by all means necessary.

In 1945, during the last phase of the Second World War, I was an interpreter to several Soviet Army generals in Budapest, Hungary. I observed their down-to-earth approach to warfare. They had not applied fancy military theories on how to defeat the Nazis. They just applied brutal military force.

The same thing is happening now in Ukraine.

During the past decade, the United States and NATO have quietly equipped and trained the Ukrainian military. Thus, it was able to resist the current Russian invasion and inflict heavy casualties on Russian troops.

History presents a few lessons on what happens when a dictator prevails pursuing an aggressive policy. During the Spanish civil war in the 1930s, Gen. Francisco Franco’s forces received all the military aid they needed from Nazi Germany and Fascist Italy. Aid from Western democracies to the leftist-leaning legitimate Spanish government was lacking. Franco prevailed, and Spain for decades became a Fascist dictatorship.

Hitler got away with sizing the Ruhr, Austria, then Sudetenland, from democratic Czechoslovakia. The result was the Second World War.

Putin has miscalculated not only how fiercely the Ukrainian military and population would resist the Russian military invasion, but also the response from the West to it.

Instead of sowing discord among NATO members, the invasion united them. It awakened Europe and the rest of the world to the danger of a revanchist Russia, intent to restore the Soviet Empire.

It is too early to tell what will be the outcome of the war in Ukraine. It can go on for months, using Russian airpower to destroy the country, while seizing large chunks of the territory, with boots on the ground.

Putin may also seek a face-saving solution. Occupying parts of Ukraine that has sizable Russian-speaking populations and proclaiming victory, hoping that the West, after much huffing and puffing, will accept the occupation as it has largely accepted the Russian occupation of Crimea since 2014.

Robert Gates, the former secretary of defense, currently serving as chancellor of the College of William & Mary, in a recent TV interview said that for him the best safeguard to any external threat to the United States is a strong military.

Now, more than ever, it is essential that the United States should be seen as reliable protector of democracies around the world.

(Shatz is a former resident of Lake Placid and a current resident of Williamsburg, Virginia. He is the author of “Reports from a Distant Place,” a compilation of his columns.)