It's a sweltering day, unusual for Santa Cruz. Eli and Lizzy and I are enjoying a friend's swimming pool. Eli is splashing and diving deep to retrieve things from the bottom of the pool. Lizzy is weightless in one of those floating baby seats with grave warnings written all over the side. I'm hanging on to the side of her tube, talking to her under her broad blue hat.
      Eli pops up and says, "Let's all be whale sharks, Mama. You be the Mama whale shark, I'm the kid whale shark and Lizzy can be the baby whale shark." We swim together through the deep end searching for food.
      A few minutes later, Eli changes the play. He says excitedly, "Let's have weapons, Mama."
      "Okay," I say, grabbing him and kissing him as he treads water, "I'm shooting you with my love gun."
      He laughs, then starts handing me imaginary weapons: "Here's a sword. Here's a machine gun. Here's an A-bomb."
      I'm taken aback. Did my four-and-a-half year old just hand me an A-bomb? I say to him: "I guess you didn't like my idea of the love gun."
      "Oh," he replies casually, "I have one of those too."
      Part of me wishes I could go along with his fantasy, but I can't. Moral Mom is dying to speak up. "Eli, where did you hear about A-bombs?"
      "From Tal." Tal is his twelve-year-old friend.
      "And what did Tal tell you about them?"
      "That they're the most powerful."
      Oh, so that's what this is. Four-year-olds-need-to-feel-powerful stuff. He's talking about A-bombs for the same reason he likes to be Tyrannosaurus Rex after breakfast.
      But these aren't dinosaurs he's talking about. They're A-bombs. I feel compelled to continue: "I don't like A-bombs."
      "Why don't you like A-bombs, Mama?"
      "Well, their only purpose is to kill people. Lots of people."
      "Tell me all about A-bombs, Mama."
      I hesitate, unsure where to start. "A-bomb stands for atom bomb. Atom bombs were developed when scientists learned how to split atoms. A long time ago, in World War II, our country was in a war and nobody knew how to stop it. So we set off two A-bombs in Hiroshima and Nagasaki. Thousands and thousands of people died. Some died right away. Others died slowly and painfully from something called radiation. Some lived but had kids who were sick. It was really terrible. It's not something I can play around with."
      Eli's face is grave with real concern. I wonder if I've gone too far. Then he looks at me reassuringly and says, "It's okay, Mama. Really. This is all just pretend."

      Moments later, Eli starts up again: "Tell me everything you know about explosives."
      I don't know much, but I manage to talk about TNT, dynamite, blasting through mountains to build railroads, and people who get paid a lot of money to blow up old buildings just right, so they collapse inwardly and nobody gets hurt. We talk about fireworks, how beautiful and dangerous they are. Eli listens, a rhapsodic sponge. Then he asks, "So is an A-bomb the most worst one there is?"
      "Yeah, Eli," I say. "It's the worst."

      When Eli was two, I was horrified at the thought that he would ever play with guns. I never bought him weapons, let him watch TV, took him to movies or let him aim his finger at anyone. But somehow, despite my best efforts to protect him, guns started cropping up in his play about a year ago. Now he's graduated to A-bombs.
      It makes me wonder. What drives a sheltered, sweet four-year-old to develop a fervent interest in A-bombs? Why do all the boys I know who are forbidden to have guns make them out of their peanut butter and jelly sandwiches? What is it about war and weapons that makes them such enduring play themes?
      The urge to feel powerful, strong and invincible is characteristic of four-year-olds. Maybe Eli's A-bomb helps him feel safe in a big, scary world full of challenges. Maybe he's right when he tells me it's just pretend; that there's a difference between the A-bomb he hands me in the pool and the ones that threaten the future of our planet.

      Later that same day, as we snuggle together on the couch, Eli says, "Let's have a love bomb." We both make exploding sounds and then blow kisses and hugs at each other. Lizzy looks up and laughs her perfect, infectious laugh. We can't help but join in.
      "Love bombs are a pretty nice kind of bomb, aren't they Mama?"
      "Yes, they are," I reply, taking an incoming kiss on my shoulder.
      "When I grow up, I'm going to invent love bombs. They'll be full of people and when they explode, the people will kiss and hug everybody that's near the bomb. Everybody in this whole continent, let's throw a love bomb at them!"
      I add an idea of my own: "You know how the other bombs are called 'A-bombs?' Let's call these 'L-bombs.'"
      "Okay, Mama, how about another L-bomb?"
      "Sure," I say.
      He giggles, aims, then dives into my arms for the kill.