Victor Davis Hanson is a classicist and historian at the Hoover Institution, Stanford University, and the author most recently of The End of Sparta. You can reach him by e-mailing author@victorhanson.com.

The newly elected French Socialist president, François Hollande, is warning Germany that Mediterranean ideas of “growth,” not Germanic “austerity,” should be the new European creed. No surprise there — reckless debtors often blame their own past imprudence on greedy creditors, especially if the latter are supposed to be guilt-ridden over causing two world wars.

All over Europe, the gospel is that tight-fisted Germans are at the root of the European Union meltdown: They worked too hard, saved too much, bought too little, and borrowed not at all. All that may be true, in theory. But, in fact, faulting thrift and industry is a prescription for incurring anger and guaranteeing backlash — especially in the case of the Germans, who are now being asked to provide even more capital to help other European economies recover.

There is one general rule about the history of the modern state of Germany since its inception in 1871: Anytime Germany has been both unified and isolated, armed conflict has followed.

We often scoff at such quaint historical laws — forgetting that World War I followed from the inability of the French to harness German nationalism after the Franco-Prussian War. World War II was a result of the inability of the victorious allies either to dismantle the unified German state or to incorporate a defeated Germany into some sort of continental alliance....