What was Hitler's argument for attacking other countries? You might think he didn't have one, but he did. His argument is frankly Malthusian: Our population is growing, and we will run out of food unless we get more land. (My colleague David Levy tells me that Malthus wasn't a Malthusian, but that's a topic for another day!) It's all in chapter four of Mein Kampf:
The annual increase of population in Germany amounts to almost 900,000 souls. The difficulties of providing for this army of new citizens must grow from year to year and must finally lead to a catastrophe, unless ways and means are found which will forestall the danger of misery and hunger.
Hitler then reviews various policies to deal with the threat of over-population:
1. Artificial birth control. Hitler rejects this because it short-circuits natural selection. Furthermore, there is an international prisoners' dilemma: The one country that lets its numbers rise will outnumber and militarily dominate the rest:
But if that policy be carried out the final results must be that such a nation will eventually terminate its own existence on this earth; for though man may defy the eternal laws of procreation during a certain period, vengeance will follow sooner or later. A stronger race will oust that which has grown weak; for the vital urge, in its ultimate form, will burst asunder all the absurd chains of this so-called humane consideration for the individual and will replace it with the humanity of Nature, which wipes out what is weak in order to give place to the strong.
2. Increasing productivity via "internal colonization." Hitler rejects this on a priori Malthusian grounds - there is no way for productivity to permanently outpace population growth:
It is certainly true that the productivity of the soil can be increased within certain limits; but only within defined limits and not indefinitely. By increasing the productive powers of the soil it will be possible to balance the effect of a surplus birth-rate in Germany for a certain period of time, without running any danger of hunger. But we have to face the fact that the general standard of living is rising more quickly than even the birth rate. The requirements of food and clothing are becoming greater from year to year and are out of proportion to those of our ancestors of, let us say, a hundred years ago. It would, therefore, be a mistaken view that every increase in the productive powers of the soil will supply the requisite conditions for an increase in the population.
3. Acquire new territory outside of Europe. The problem with this plan, says Hitler, is that other European countries have already taken the good non-European land. So you would have to attack European countries to get the land:
In the nineteenth century it was no longer possible to acquire such colonies by peaceful means. Therefore any attempt at such a colonial expansion would have meant an enormous military struggle. Consequently it would have been more practical to undertake that military struggle for new territory in Europe rather than to wage war for the acquisition of possessions abroad.
4. Acquire new territory inside Europe. At last, a solution to the imbalance between people and land that Hitler likes! And of course, he doesn't contemplate buying the land:
Of course people will not voluntarily make that accommodation. At this point the right of self-preservation comes into effect. And when attempts to settle the difficulty in an amicable way are rejected the clenched hand must take by force that which was refused to the open hand of friendship. If in the past our ancestors had based their political decisions on similar pacifist nonsense as our present generation does, we should not possess more than one-third of the national territory that we possess to-day and probably there would be no German nation to worry about its future in Europe.
5. Last, Hitler briefly mentions increasing exports to buy food, but dismisses it almost without consideration.
Linking views you don't like with Hitler is of course the ultimate political cheap shot. But as an economist, I don't mind buying cheap, especially if the quality is good. When someone says "There are too many Jews," we suspect that he wants to kill Jews. Similarly, it turns out that at the root of Hitler's propensity to kill people was his belief that there are too many people.
And if you're tempted to say that Hitler proposed a barbaric solution for a real problem, take a look at how Germany actually did feed its population since 1945: increasing agricultural productivity and increasing exports. The two methods that Hitler dismissed out of hand transformed Germany into one of the richest nations in history.
For more on the history and economics of Nazism, check out my article on fascism, forthcoming in the Encyclopedia of Capitalism.