After Pearl Harbor was bombed Dec. 7, 1941, US Navy ships rushed through the Panama Canal and went on to help win World War II.
At the time, the shortcut between the Atlantic and Pacific Oceans was considered so crucial that some 50,000 US troops guarded it.
Nearly 60 years later, the US will pack up its military operation, and walk quietly away from that same canal.
The decline in the canal's importance has been difficult for many Americans to fathom. As Ronald Reagan said in a sharp attack on the 1977 decision to turn over the five-mile-long waterway, "We bought it, we paid for it, it's ours. Let's keep it."
But the reality, analysts say, is that the Panama Canal no longer matters as it once did. And the same can be said for the other strategic choke points throughout the world - from the Strait of Gibraltar, which separates Africa and Europe, to the Strait of Hormuz, which links the Arabian Sea and the Persian Gulf.
"We are entering a transitional period," says Harlan Ullman, a naval-strategy specialist at the Brookings Institution in Washington. "At the end of the 20th century, the choke points are moving to cyberspace and economic markets."
One reason has to do with today's global power scheme. The US is a lone superpower and has capable fleets in both the Atlantic and the Pacific. In the case of the Panama Canal, Navy officials say cross-ocean ship movement is no longer crucial enough to justify military control of the waterway.
Meanwhile, across the Atlantic, Europe is uniting and expanding, and internal rivalries are no longer fought on the seas.
Moreover, throughout the world, militaries increasingly project power by air. Oil is transported by pipeline. And information is bounced off satellites well above the earth's waters.
Importance of waterways
It was not until the first decade of the 1900s that modern naval strategy recognized and emphasized the importance of a handful of narrow waterways - which, if controlled, could result in disproportionate power. Then, Britain ruled the seas, but it was facing increasing competition.
Sir John Fisher, the commander in chief of the Royal Navy, began to transform Britain's fleet from stationary to mobile. He coined the phrase "choke point" and asserted that Britain would have to control them - and move through them - if it were to retain its water dominance.
But well before Sir John pinpointed his country's strategy, most choke points had histories of war and conquest, and were won and lost with the ebb and flow of global dominance.
The Dardanelles, which links the Aegean Sea to Istanbul, was contested dating back to 480 BC. In World War I, the British-French alliance made a run for it, but eventually lost to Turkey.
Today, Turkey is a member of NATO and a candidate for the European Union. Dardanelles is no longer considered a flash point between East and West, but a bridge between the Muslim and Christian worlds.
The opening in 1869 of one strategic choke point, the Suez Canal, buoyed the importance of another key waterway, the Strait of Gibraltar. Combined, they link the Atlantic and Indian Oceans - and allow ships to bypass Cape Town, the southern tip of Africa.
The Suez Canal was built by the French, controlled by the British, and claimed by Egypt in 1956 in an unusual military standoff in which the Soviet Union threatened to intervene and the United Nations eventually was able to defuse. Gibraltar was won by Spain in 1462, but taken by the British in 1830.
One example of the Suez Canal's lessening importance in the modern era, analysts say, is that it was closed from the late 1960s until 1975 - without a major disruption to commerce. Meanwhile, in 1985, Spain essentially gave up its claim to Gibraltar by lifting a 16-year border blockade.
The key choke point in Asia is the Strait of Malacca, which is the shortest route linking three of the world's most populous countries - India, Indonesia, and China - with Japan. The strait has been controlled by the Arabs, Portuguese, Dutch, and British. While it is still an important passage, Malacca has waters that are too shallow for some ships.
Finally, the Strait of Hormuz is a relatively new choke point, which gained economic significance when oil tankers began transporting fuel from the Persian Gulf. Although still critical for the US - especially if it wants to keep oil prices low - its importance has been diminished by Saudi Arabian pipelines.
While the overall decline of geographical choke points applies most to strategic military value, analysts point out that the commercial value of the waterways cannot be taken for granted - especially with the expansion of world trade.
"There are some aspects of the new interdependent world that make the straits less important," says Doug Johnson, a naval expert who is president of the International Center for Religion and Diplomacy in Washington. "But there are other aspects that make them highly critical, such as facilitating open trade."
By giving up control of the Panama Canal, the US may be defying history, which has seen world powers come and go and strong navies spring up in a matter of years.
"Ten or 15 years from now we may really wish we had the Panama Canal," says Jon Sumida, a naval historian at the University of Maryland in College Park. "But if we thought that way, we'd never secede territory and we'd have a recipe for expansionism."
Some analysts fear giving up control of the canal because, in the event of war, an enemy could block the waterway and prevent US ships from moving back and forth. A blockage could also disrupt commerce, although the disruption would not be drastic.
Some politicians worry about the company that will run ports on either side of the canal, Hutchison-Whampoa. They say the company is dangerous because it has ties to the Chinese Army, which may be using the ports to get a foothold in the region.
A senior Pentagon official involved in turnover security called those worries "absolutely ridiculous." Other officials have said that there is no need for concern because the US could easily defend the canal from afar.
Threats by drug cartels
Perhaps a more feasible threat is that the Panama Canal could be the target of terrorists - possibly from a drug cartel in neighboring Colombia.
"We are not aware of any current internal or external threat to the Panama Canal," a department of Defense spokesman said in a written statement. "That said, the Panama Canal is a potential target for hostile forces given its importance to global commerce and military transits."
About 50 military ships have traveled through the canal this year, but the major carriers and battleships are too big to fit in the locks that raise and lower vessels to the changing water levels.
If straits and canals are becoming the global choke points of the past, then the Internet and world economy are becoming the choke points of the future.
Already world powers are waging high-tech battles to control and defend information systems and cyberspace. And the US, more than any other country, uses its economic might to strengthen its position around the globe.
While a blockage of the Internet would devastate economies and stock markets, a shutdown of the Panama Canal would barely register on most of today's economic indicators.
"It's harder to use the choke points to cause difficulties," says John Hattendorf, a maritime professor at the US Naval War College in Newport, R.I. "Militaries are more flexible and they can move faster - especially the US. There hasn't been a threat to the world's sea lanes since the end of the cold war."
(c) Copyright 1999. The Christian Science Publishing Society