The limitations on our war-making are just as often self-imposed. Yes, we defeated the Axis powers in less than four years, but it was at a ghastly cost. To defeat both Japan and Germany, we averaged over 8,000 Americans lost every month of the war — compared to around 50 per month since Sept. 11.

So far the United States has encouraged its citizens to shop rather than sacrifice. The subtext is that we can defeat the terrorists and their autocratic sponsors with just a fraction of our available manpower — ensuring no real disruption in our lifestyles. That certainly wasn’t the case with the Depression-era generation who fought World War II.

And in those days, peace and reconstruction followed rather than preceded victory. In tough-minded fashion, we offered ample aid to, and imposed democracy on, war-torn nations only after the enemy was utterly defeated and humiliated. Today, to avoid such carnage, we try to help and reform countries before our enemies have been vanquished —putting the cart of aid before the horse of victory.

Our efforts today are further complicated by conflicting Internet fatwas, terrorist militias and shifting tribal alliances; in short, we are not always sure who the enemy cadre really is — or will be.

So paradoxes follow:

A stronger, far more affluent United States believes it can use less of its power against the terrorists than a much poorer America did against the formidable Japanese and Germans.

World War II, which saw more than 400,000 Americans killed, was not nearly as controversial or frustrating as one that has so far taken less than one-hundredth of that terrible toll.

And after Pearl Harbor, Americans believed they had no margin of error in an elemental war for survival. Today, we are apparently convinced that we can lose ground, whether in Afghanistan or Iraq, and still not lose either the war or our civilization.

Of course, by 1945, Americans no longer feared another Pearl Harbor. Yet, we, in a far stronger and larger United States, are still not sure we won’t see another Sept. 11.