It should not be surprising that the leaders of the British Empire decided to use the same genocidal tactics as the Nazis in World War II. Americans used similar tactics against the Native American Indians and later against the Philippine Islanders and the Vietnamese (to keep the list short). Mass murder is a strategy that a lot of other leaders have used throughout history, limited only by their power and technologies.
Overlaying an indigenous group we can call Celts (though they also were a mix of invaders and indigenous peoples), the people we call English are a mixture of Germans (Angles and Saxons), Vikings, Danes (who were just well-organized Vikings) and eventually the Normans, who were slightly Frenchified Vikings.
If you enjoy Vikings on The History Channel, you can see the leadership qualities of later-day leaders in Ragmar Lothbrok, brilliantly played by Travis Fimmel. A calculating greed and willingness to unleash mayhem eventually allowed these barbarians and their descendents (including cultural as well as genetic descendents) to conquer most of the world.
Being allied with the British, we Americans have been taught a great deal about Hitler's (and Tojo's) war crimes, but very little about our own. But this essay is not meant to recount those crimes. Here they serve as fodder for an exploration of opportunity costs. As in so many things, it is easier to see opportunity costs in retrospective than in the present or in the future.
For a more detailed (but still brief) review of opportunity costs in World War II, specifically those associated with aerial bombardment, I would recommend "Opportunity Costs" by Edward Luttwak in the November 21, 2013 London Review of Books [subscription required], which in turn is a book review of The Bombing War: Europe, 1939-1945
by Richard Overy.
In summary, mass murder, including genocide, is not always the best tactic. The British did very little face-to-face fighting with the Germans; that was left to the Russians [resulting in an atheist holocaust]. The Germans wasted effort (men and materials) killing their perceived internal enemies. The British used up (threw away) astonishing resources in their failed attempt to firebomb Berlin (though they succeeded in firebombing other cities). If the atomic bomb (which the British helped develop) had not worked (or just taken longer to get working), it might be argued today that using the same resources to advance other high-technology weapons would also have forced Japan to surrender earlier, if not unconditionally.
Every choice made implies choices not made. Resources devoted to the military deprive the civilian sector, and vice versa. In California the current drought has intensified the usual fight over the allocation of water to farmers, fish, and urban/suburban uses. Opportunity costs are the losses created when resources are not devoted to a particular pathway.
Forcing (or tricking) an enemy to waste resources is a classic strategy. Much of modern warfare has been quantified: the cost of wiping out a village in Vietnam with napalm, as opposed to the cost of winning over the village by providing running water or other desirable goods. So too it is possible to quantify the opportunity costs that different strategies and tactics might inflict on an enemy. The reason Al Qaeda is, on the whole, winning its war against the U.S. and our (more or less) allies is not based on large masses of people buying a peculiar brand of Islam. Al Qaeda has encouraged the largest waste of resources in history, by the United States. Al Qaeda has grown its capabilities while the U.S. has reaped a national debt that will cripple it for the rest of history.
Even before 2001 the U.S. wasted a lot of money on its military establishment. It could be argued that military expenditures in the brief era between the end of the war on Communism and the war on Islam might have been necessary to maintain America's commercial empire. But clearly the decision to invade both Afghanistan and Iraq while building an unprecedented Homeland Security force (and not raising taxes to pay for it) meant making sacrifices in the domestic economy. We have had two major recessions since 2001. Meanwhile, China, mostly at peace with the world, has grown to be a serious economic rival.
Some opportunities slip away with time. Education is a good example. The children who did not get enough education in first grade in 2002 are now mostly in their first year of work (or unemployment) or first year of college. We are working on creating a full generation of people who could have been better educated if there had been less spending on security. They, in turn, are and are going to be less economically productive than they could have been.
The national debt ($17 trillion), which may have complex sources but which I think can be fairly blamed on an inappropriate response to Al Qaeda, is now seriously limiting what the federal government can accomplish. It can stand as a proxy for the opportunity costs of bad political decision making. As interest rates rise the payments on the debt will cut further into the budget. I project that within five years both military and education budgets will need to be cut dramatically, at the same time taxes are raised, if the U.S. is to avoid bankruptcy.
Population control and (its close relative) global warming are time-sensitive issues where the bulk of the opportunities have now been lost. A one-and-done (1 child per family) global program would take so long to institute that the bulk of its effects would likely take place long after some other cause (war, disease, and famine, most likely).
Global warming is not likely to decelerate. Manufacturing more solar panels just adds more greenhouse gasses now, making people feel good about their energy consumption and breeding habits. Stopping global warming would require a bottoms-up fundamental change of how humans live, even if the population began to fall for some reason. Global warming itself won't kill many people, not anytime soon. It will cause negative feedback, but at too slow of a pace to be of much help reducing the homo sapiens plague.
Is there hope for the human population of the world? In Barack Obama's speeches, yes. But not in his policies, or those of other world leaders.
But don't worry, the U.S. and global economies should continue to pick up until the next round of free-market or government-mandate human folly precipitate another crisis. Environmentalists will use slightly less energy than their non-enviro neighbors, who are limited only by their ability to cope with their energy bills. People will pass on their culture of failing to educate, failing to take care of the planet, and failing to take the long view.
Pessimistic analysis is not popular. Happy talk is the order of the day. But I did not want to miss the opportunity to be straight with you on Darwin Day.