Even after Hitler invaded Czechoslovakia and Poland, a strong pacifist movement in Britain opposed a military buildup to confront Nazi Germany. It vilified Winston Churchill as a warmonger for pushing one.

“What is it that Britain and France are fighting for?” Churchill asked rhetorically in a March 1940 broadcast. “If we left off fighting you would soon find out.”

Five months later, bombs started dropping on London. Britain found itself alone and teetering on the edge of an invasion by Nazi Germany. And in these dark hours, when a militarily weak Britain suffered frightening losses on the battlefields, politicians who opposed preparing for war blamed Churchill for being a poor wartime leader.

Climate change is a very different kind of peril, but it, too, is menacing our planet with catastrophic consequences for both our natural environment and built civilization. The warnings have been coming fast and furiously for years as the powers in Washington lifted not a finger to deal with the danger. Worse, many denied it is real.

Now listen to Cathy Crain, mayor of Hamburg, Iowa, whose Missouri River town was inundated to the rooftops by apocalyptic flooding.

“I’m looking at global warming — I don’t need to see the graphs,” Crain said. “I’m living it and everybody else is living it.”

Americans are finding out why they must fight. They see the devastating fires, droughts, hurricanes and tornados. They watch towns and beautiful farmland in Iowa, Nebraska and Missouri disappear under the water.

And it’s just started. The National Oceanic and Atmospheric Administration says 25 states could see moderate to major flooding through May. Some will surpass the infamous floods of 1993 and 2011.

Natural disasters have always been with us. Responsible climate scientists are careful not to place all the onus for these events on rising temperatures. But they do insist that climate is playing a part, and that as the Earth gets warmer, these calamities will grow in degree and number.

Still, the appeaser politicians have no answer other than to spend zillions of taxpayer dollars on fixes that won’t work for long. And where will that money come from? Many of these same officials lustily supported the Trump tax cuts, which are draining the Treasury of needed revenues.

Case in point is Missouri Sen. Josh Hawley. When the subject came around to climate change, the Republican pointed fingers at the all-purpose “radical environmentalists” for killing jobs. Now he blames them for allegedly forcing the Army Corps of Engineers — which oversees flood control efforts — to favor wildlife over farmers.

The corps serves several constituencies, but as its deputy commanding general for civil and emergency operations said in a recent statement, “The Corps’s No. 1 priority in its operations is life safety.”

Thing is, for over a century, the corps has been building, building, building levees, spillways and other infrastructure to control the waters. This system is crumbling under the pressure of climate-induced flooding. You could build levees seemingly halfway to heaven with more borrowed money, but in many cases, they won’t meet the growing challenge.

And even when levees — built or sometimes removed — succeed in preventing floods in one place, they can create problems elsewhere. After all, the water has to go someplace. When a levee was demolished in 2011 to save Cairo, Illinois, from a rampaging Mississippi River, some 100,000 acres, mostly farmland, was flooded.

In his previous job as Missouri attorney general, Hawley joined a suit against Barack Obama’s Clean Power Plan, designed to contain global warming. President Trump applauded.

With leadership like this, the war against climate change hasn’t even reached the end of the beginning. Surrender and blaming others is not a winning strategy.

Froma Harrop is a syndicated columnist. Follow her on Twitter @FromaHarrop. She can be reached by email at: fharrop@gmail.com.