By Stephen Kent |Catholic News Service

While searching for a strategy to deal with a murderous band of thugs, called the Islamic State by some, the nation's leadership must evaluate how this strategy will be implemented.

The Islamic State poses a perplexing question because it is not a nation upon which we can declare war. It is a large group of criminals for whom international law has no effect or meaning. They carry out terribly inhumane acts and must be brought to justice.

Use of force is a legitimate method to bring about an end. Force may be used when persuasion fails, just as a police officer may use force properly to subdue an offender to protect public safety.

Pope Francis said recently, "Where there is unjust aggression, I can only say that it is licit to stop the unjust aggressor." But how?

"The means by which he may be stopped should be evaluated," the pope said.

Day after day, we hear reports of Islamic State militants kidnapping children, beheading American journalists and conducting ethnic cleansing and mass executions. This barbaric behavior generates hatred, a feeling so strong that it can generate thirst for revenge.

These times call for restraint, a curb on this primal thirst.

There is need to use force, but since these terrorists live among the population, rockets and bombs can't be dropped on a village of largely innocent civilians in order to deal with a few evildoers.

After Germany surrendered in 1945, attention quickly shifted to the war against Japan. It has been widely accepted that the U.S. dropped the atomic bomb on Japan to avert the need for an invasion, avoiding large-scale American casualties.

Paul Ham, an Australian journalist, raises some disturbing points in his book, "Hiroshima Nagasaki: The Real Story of the Atomic Bombings and Their Aftermath."

He asks: Was it necessary?

By 1945, Japan was already defeated militarily on land, in the air and on the sea, writes Ham, and defeated economically as the result of the U.S. naval blockade. Fire bombings had destroyed 66 cities; several hundreds of thousands were dead.

Despite this, plans to drop the bomb went forward.

The Pentagon projected 31,000 U.S. causalities, far below the 500,000 later used to justify the two attacks.

Invasion plans were called off in 1945, weeks before the first atomic bomb was tested in the New Mexico desert, Ham wrote, effectively eliminating the invasion as an excuse for the bombing.

Woven through Ham's narrative is the political climate at the time: Americans were rightly outraged about the sneak attack on Pearl Harbor, the Bataan Death March (a torturous transfer of Filipino and American prisoners of war) and abuse of prisoners of war by the Japanese. There was little empathy for a barbaric enemy. There was hatred and need for revenge.

The war could have ended, Ham says, without a "boots on the ground" invasion and without the death and suffering resulting from the two atomic bombings. The continuation of the blockade would just wait for Japan to die on the vine.

The doubts Ham raises can be debated. But they are pertinent today as the nation again confronts those whose culture we don't understand, whose way of thinking is incomprehensible.

Hatred and revenge greatly influenced the atomic bomb decision. This time, when evaluating what action we'll take, any decision must be protective of civilians and have a clearly defined mission to halt uncivilized behavior.

Kent is the retired editor of two archdiocesan newspapers. He can be contacted at: [email protected].