“How should, in fact, Israel respond when Hamas launches thousands of rockets?” Ryan asked. On my Facebook page, Joel put it this way: “Mr. Kristof, what do you recommend that Israel do in response to rocket attacks? What would the American response be to repeated rocket attacks from Mexico or Canada on American cities?”

We probably would not turn the other cheek: When the Mexican revolutionary leader Pancho Villa attacked a New Mexico town in 1916, the United States sent 6,000 troops into Mexico (albeit after getting Mexico’s permission). And in response to the 9/11 attacks, America invaded both Afghanistan and Iraq. Yet it’s also fair to note that this impulse to lash out didn’t work out any better for America than it has for Israel: Pancho Villa escaped, our ruinous Iraq war benefited Iran, and we are now retreating from Afghanistan with the Taliban resurgent. As we’ll see, other countries have dealt with attacks far more judiciously.

More to the point, though, the question of how the U.S. would respond reflects a myopia about the origins of Hamas shelling.

“Israeli officials did not wake up one bright morning to find thousands of rockets raining down,” notes Sari Bashi, an Israeli human rights lawyer. “Israeli security forces, led by a prime minister desperate to stay in power to avoid jail on corruption charges, created a provocation by using violence and the threat of violence against Palestinians in Jerusalem. They stormed a sensitive religious site, used excessive force against demonstrators and threatened to forcibly transfer Palestinian families from their homes as part of an official policy to ‘Judaize’ occupied East Jerusalem, which is a war crime.”

So the question of how the United States would respond if Canada started shelling Seattle seems misplaced. After all, Israel deliberately nurtured Hamas in the first place (to create a rival to existing Palestinian groups), and the United Nations and most experts consider Israel to be occupying Gaza (because Israel controls it, even though it withdrew in 2005). As Bashi, who is now research director at Democracy for the Arab World Now, puts it: “A better question would be: ‘What would the U.S. do if it conquered and occupied British Columbia, and then Canadian armed groups, resisting the occupation, shelled Seattle?’”

Hmm. A bit more complicated.

Meanwhile, let’s note that other countries have responded to attacks with more restraint and wisdom than either Israel or the United States. India and Afghanistan have repeatedly suffered terrorist attacks plotted in Pakistan; one such series of attacks in 2009 in Mumbai killed 164 people. India did not respond by shelling Lahore or Islamabad but with diplomacy. These analogies are inexact and imperfect, yet this lesson emerges: No peace deal between Israel and Palestinians is achievable today, but there are steps that make peace more possible 15 years from now and those that make it less likely. Every time Hamas shells Israel, it makes a solution less likely. And every time Israel grabs more land or kills more children, it likewise makes peace less achievable. Extremists on each side empower those on the other.

There is no doubt that Hamas committed war crimes in shelling Israeli civilians. But most scholars believe (with not quite the same certainty) that Israel also committed war crimes with its attacks on Gaza that were far more lethal to civilians than attacks by Hamas.

A basic principle of getting out of a hole is to stop digging. A basic principle of peace-building is to stop committing war crimes. That’s the only path to making insoluble problems solvable.