Commodity prices rose across the board on Thursday, with oil surging up roughly 5 percent to more than $120 a barrel. No single fact seems to have caused Thursday’s broad rise — economic data recently released were, if anything, bearish — although many have pointed to a 1 percent drop in the value of the U.S. dollar. As the trading logic goes, if one does not trust the dollar, one can always sell it to purchase “stuff” such as nickel, copper, oil and whatnot. The logic holds doubly if one expects the dollar to get weaker still.

Regardless of the reason for the commodity price increases, they most certainly have happened — and happened in force.

I can’t predict commodity prices (oh if I could!); instead, I’ll endeavor to predict what their effects will be on the geopolitical constellation of the day. As I have argued in the past, sustained high commodity prices at this level begin to have very real geopolitical impact, and can begin to influence the rise and fall of nations as oil- and mineral-rich backwaters reap record gains and unfortunate importers of everything from natural gas to grains suffer a tangible setback on the world and economic stage.

But there is something else I would like to note. If prices rise but a touch on today, the increase for the week will have been the strongest since 1975. That number — 1975 — is one that catches my attention.

For those of us who remember the mid to late 1970s, it was a scary time. The Soviets were coasting on record-high oil revenues and were on a tear internationally. Moscow’s subsidies and arms sales made the world seem as if it were on fire and the Cold War had been lost. The sustained strength in commodity prices almost single-handedly caused economic stagnation in the United States and made inflation a globally entrenched phenomenon.

Compare that with what is happening today. The Russians are coasting on record-high oil and natural gas revenues, and they have just de facto conquered a neighbor. Moscow is flirting with Cuba, Venezuela, Syria and Iran about weapons sales and/or basing rights. Iraq could still be described as smoldering, Afghanistan is most certainly on fire and U.S. forces are overcommitted and thus ill equipped to deal with any new blazes should they ignite. The U.S. economy has certainly slowed down — if not outright contracted. Commodity prices, which have strengthened steadily for the past three years, have pushed inflation on the global level up to decade-plus highs.

I’m not saying that the 1970s are returning. There are a thousand things — from the weather in Cuba to thugs in Nigeria to grandstanding in Venezuela to tanks on the Russian steppe to loan policies in Tokyo — that affect the price of tea in China. Prices could rise tomorrow or next week, or they could not.

What I am saying is that the events of Thursday, Aug. 21, 2008, while dramatic, do not exactly put us into uncharted territory. The day had a familiar feel to it — and “familiar” does not necessarily mean “warm and fuzzy.”