Ukrainian soldiers carry the coffin of a fallen comrade toward Saints Peter and Paul Garrison Church for the funerals of military personnel Ruslan Koval, 49; Viacheslav Ubyivovk, 44; and Liubomy Gudzeliak, 37, in Lviv, Ukraine, on April 6. They died in action in the Luhansk region, where heavy fighting rages as Russia refocuses its attention to the eastern areas of Ukraine. (MAURICIO LIMA, New York Times/The Minnesota Star Tribune)

The world needs to stop the killing in Ukraine. The United Nations, the United States, the European Union, NATO and the Western democracies need to act. It's time to stop the murder of men, women and children in Ukraine and the destruction of their land and heritage.

The world dares to be timid in the face of brutality, murder and now atrocities. It's time to act! I firmly believe that the fear of a Third World War or a nuclear attack is unfounded and overblown. Putin is a criminal, but I don't believe he is stupid. He knows that were he to resort to the "nuclear option" to win control of Ukraine, he and the Russian people would lose. I learned during the Cold War, and Putin knows, that the U.S. and NATO have a significant advantage in thermonuclear firepower and Russia could potentially and tragically be "bombed back into the Stone Age."

This is not warmongering. It is the humane, moral and righteous right of the world to stop the killing of innocents and protect the sovereignty of a European nation. What do we know about brutal dictators? We know they fear and respect strength. Particularly massive strength arrayed against them.

If you can't fight, then write. National opinion polls reveal that the majority of Americans want the U.S. "to do more" to stop the killing in Ukraine. This is how the U.S. can do more. Write your elected and appointed officials in Washington (the White House, Congress, Department of Defense) urging them to take action to bring the war to an end. Let's not regret or lament that we chose inaction.

There is precedent. The world left Ukraine to the Russian wolves, but in the past, the world acted. We expelled the Iraqi Army from Kuwait.

On Aug. 2, 1990, the Iraqi Army, the fourth-largest in the world, invaded its neighbor Kuwait. The U.S. responded to "preserve the sovereignty of nations" with Operation Desert Shield/Desert Storm. The multinational effort brought together the largest force of Navy warships assembled in a single theater since World War II.

Faced with a multinational armed force, superior air power and the resolve of the world, the Russian Army would retreat. Clearly it would not advance farther. The Russians are currently stalemated in Ukraine.

That creates a major opportunity and a frightening threat. Putin may react in anger and revenge to the stalemate and increase Russia's siege and bombardment of Ukrainian cities and civilians, causing more deaths, suffering and war crimes.

Now is the time to tip the scales to save the Ukrainian people and nation.

It's time to act before the strategic situation changes. And maybe daring to defend Ukraine would give Putin an "off-ramp" — a way out of the mess he created. A cease-fire in front of a multinational force might be more palatable to him than being stymied by a smaller Ukrainian resistance.

The most significant action the world can take to save lives and stop the aggression is to bring into Ukraine a robust air defense system. Owning the skies could well be the best way to end the conflict. A multinational force, with air dominance, could move into western Ukraine before the Russians could get there. Our aim would be to ensure that humanitarian corridors are established and protected to save lives, to halt the war and to bring peace and security to the battered people of Ukraine.

Remember the Cold War? Peace through strength kept the peace. It was more than just a campaign slogan. It worked!

Air cover along with protected routes would allow civilians to escape from the deadly bombardment in the east. Eventually it would be safe for the more than 10 million Ukrainian refugees to return to rebuild their lives and their land.

Ours would be a defensive posture to prevent further expansion of the invading Russian army and to protect the Ukrainian people from further death from the air by Russian artillery, bombings and missile attacks. Again, I could be wrong. But I do not believe that Putin would challenge the world and risk defeat by a large and determined multinational presence. We did it in the Middle East. Let's do it in Europe. Stop the killing!

David Francis, of Stillwater, is a retired U.S. Navy captain and former nuclear missile submarine weapons officer.