Victor Davis Hanson urges National Review Online readers to “beware international affairs” during the closing months of Barack Obama’s presidential administration.

Deterrence is a nation’s ability to discourage aggressors by instilling in them a credible fear of punishment far greater than any perceived gain that could be achieved by an attack.

Deterrence is quite different from deference, which is a courteous accommodation to the will of another, often one deemed superior.

Deterrence is ultimately enhanced by the possession of overwhelming military force, but it is unfortunately not thereby ensured.

France, the Low Countries, and the British expeditionary force had a combined larger army, more tanks and comparable air forces, when Germany nevertheless attacked in surprise fashion and destroyed them in six weeks in May and June 1940. What the Allies lacked were not the guns and soldiers but the credibility that they would use them with dispatch, skill, and determination.

Unfortunately, after eight years, Obama and his staff seem still confused over what deterrence is. The president believes that calm can be maintained through either apology and assurances or occasional tough but empty rhetoric — apparently on the premise that because the United States has overwhelming military force, aggressors would never logically cross it.

In contrast, the Neanderthals of the world assume that U.S. force is now becoming irrelevant and that the president is entirely predictable: occasionally eager to compromise and lecture, usually full of braggadocio, and always without credible follow-up. To be blunt and cruel, they find Obama the proverbial freshman loudmouth whom bullying seniors for sport enjoy separating from his lunch money.