In 1915, during World War I, Imperial Germany made a fateful decision that has rippled down to us in the recent Boston Marathon bombings. Kaiser Wilhelm, in desperation over the British naval blockade of Germany, ordered a German U-boat to sink the British ocean liner Lusitania off the coast of Ireland. Of the 1,119 passengers who died, 114 were Americans.

This act enraged Americans and was one of the leading causes of U.S. entry into the conflict. Based upon Bill Moyers’ video history of World War I, the reason Americans turned against Germany over this sinking was based upon a code of honor followed by the combatants. That honor code stated that noncombatants were not to be targeted during a war. Germany broke that code with the sinking of a supposedly unarmed passenger liner.

The torpedoing of the Lusitania caused Americans to believe that Germans were savages and barbarians, not really fully civilized or part of the modern world. That act marked a turning point in attitudes toward targeting civilians. Since that time the attitude has evolved from avoiding the targeting of civilians to making them the target.

During World War II targeting civilians became a part of Allied policy with the day and night bombings of German cities. Hundreds of thousands of civilians died because of these attacks. “If need be, as the war went on, we hoped to shatter almost every dwelling in almost every German city” (official transcript of the meeting at the Kremlin between Winston Churchill and Josef Stalin on Aug. 12, 1942, at 7 p.m.). It was anticipated that the targeting of civilians would destroy morale as well as kill industrial workers who worked in the factories.

What had been acts of barbarism by Germans in World War I had become policies of the Allies against Germany and Japan in World War II.

After World War II it was, ironically, the Jewish terrorist group Irgun that set the example of terrorism for the world by bombing the King David Hotel in Jerusalem in 1946, killing nearly 100 people. This attack would set the tone for future terrorist bombings. Those who had been persecuted became the persecutors.

With the rise of terrorist attacks, civilians became the targets rather than collateral damage. The attacks on the Twin Towers in New York on Sept. 11, 2001, are an example of this. The goal was to instill terror in Americans. It worked. The World Trade Center represented American business and capitalism. That’s why it was chosen. The attack on the Pentagon was an attack against the U.S. military. That at least made some sense for its symbolic value.

The Boston Marathon attack went one step further by picking an event that had no symbolic meaning in regard to American capitalism or government. It was a senseless blow on average Americans. For what reason? It seems just to kill and maim people.

Today, terrorism’s main goal is to kill and maim in a public way to gain as much publicity as possible. Sometimes the murders are done for religious reasons, as in the case of 9/11, and sometimes like the killings of children and teachers at Newtown, and at the movie theater in Aurora, the issue seems to be mentally unbalanced people going on a rampage.

There appears to be a common thread in all these killings: one group of people has decided to turn another group of people into objects – rather than living breathing human beings like themselves. This tendency to objectify one’s enemies is a common practice and is an excuse for treating others badly.

That seems to be the attitudes of the two young men who wreaked havoc on the Boston area in recent weeks. To them, the people they killed and maimed were really not human. They somehow were seen as different and therefore inferior to the attackers. How else could they have treated others so brutally?

That is the danger we all face in a lesser way when we deal with people who are different from us – we turn them into objects rather than people who have feelings and thoughts like we do. That is a tendency we all struggle with. Few will actually carry out such brutality as was seen in Boston and Watertown, but we all have a tendency under pressure and injustice to turn those who oppose us and who differ from us into things – objects.

That is a lesson we can gain from such terrible events.