This month's sudden national fixation on flyover spy balloons from China is far from the first time "eyes in the sky" have caused confrontations between the U.S. and rival superpowers.

Espionage has been a feature of international relations throughout history, and spying has led to many conflicts over the ages. But aerial reconnaissance and high-resolution cameras have added a sense of violation that comes intolerably close to home and raises the stakes.

But we should remember that the U.S., while surely spied upon, has been the world leader in aerial reconnaissance through at least the last few generations of technology.

Francis Gary Powers was a household name in the America of the early 1960s. For at least some Americans, that name still evokes an era when the world seemed on the brink of nuclear war between the U.S. and the Soviet Union.

Powers was an Air Force captain who had been recruited by the CIA in the mid-1950s as part of the "Second Weather Observational Squadron" that was supposed to be part of NASA but was in fact conducting overflights in search of Russian facilities producing ICBMs.

He was to conduct the last of a series of covert flights on May Day 1960, but his top-secret, high-altitude U-2 jet was shot down deep inside Russia. As the CIA had begun to suspect, the U-2 was no longer flying faster or higher than Soviet surface-to-air missiles could reach.

Russia initially announced the takedown without giving details, and the U.S. put out its story about a NASA weather mission that got off course. President Dwight D. Eisenhower personally repeated this falsehood.

But the Russians had a secret, which their Premier Nikita Khrushchev soon shared with the world. They had already found the wreckage of the Lockheed U-2 and captured Powers, who had ejected as his plane broke up. The Soviets displayed the American plane and its photographic equipment – and its pilot – to the world.

The evidence showed Powers' real mission had been to traverse the vast Soviet Union from its southern border with Pakistan to the Arctic Circle, eventually landing at a base in Norway. But he never got there.

Fallout from the act and the falsehoods

Eisenhower had been planning to hold a summit meeting with Khrushchev later in May 1960. Their meeting had to be cancelled, a major embarrassment to the Republican president and to some degree his vice president, Richard Nixon, who would be the party's nominee to succeed Eisenhower that fall.

The awkwardness of the U-2 fiasco also lent a certain credibility to the criticism leveled by the Democratic presidential nominee that year, John F. Kennedy. He and others had been trying to make the case that the Soviets, having launched the first satellite and then sent the first human into space, were winning the space race and undercutting U.S. military superiority.

Meanwhile, Powers was tried and convicted on espionage charges in the Soviet Union, then released in exchange for a U.S.-held Russian spy in 1962. Then in October of that year, another U-2 pilot took the pictures that showed Soviet technicians building missile launchers in Cuba and set off the most intense crisis of the postwar era.

Kennedy ordered a blockade and the Soviet ships delivering the missiles were turned back. It was widely considered the moment at which the world's two largest nuclear arsenals came closest to being used. From the Powers flight to the Cuban blockade, it all happened in the space of about 30 months.

Tensions in the South China Sea

More recently, in 2001 an American reconnaissance plane off the coast of China collided with one of the Chinese fighter jets that had been sent to intercept it. The incident took place in the South China Sea, about 200 miles east of Vietnam. At the time of the collision, the American aircraft was about 70 miles from Hainan, an island province of China and about 100 miles from a Chinese military base.

The Chinese plane that made contact went down and its pilot was lost. The American aircraft made an emergency landing on Hainan without having obtained permission to land.

There, the Chinese took the 24 U.S. service personnel who had been on board into custody. Ten days of negotiation resulted in the U.S. issuing two apologies, one for the collision itself and the death of the Chinese pilot and one for landing on Hainan without official permission. But the U.S. never acknowledged the aircraft had been engaged in surveillance or, as the Chinese described it, espionage.

The American crew members, who had spent their first minutes on the ground destroying equipment, instruments, documents and data, were held and interrogated but soon released, and the U.S. eventually got back the pieces of the damaged plane.

The lengthy negotiation and joint statement allowed both sides to save face. But the incident served notice that the Chinese Communist Party was aggressively guarding its turf and prepared to challenge the U.S.

Unlike the Powers U-2 incident, however, which led to a long decade of superpower tensions, the CP-3 episode was soon overshadowed by a greater crisis, the attacks of Sept. 11, 2001, and the subsequent "war on terrorism." While the U.S. used aerial reconnaissance extensively over more than 20 years of this struggle, none of the adversaries involved has been known to conduct the same kind of surveillance on U.S. territory.

That may be one reason the discovery of the Chinese balloon intrusion, and the subsequent hyper-sensitivity of the U.S. government to unidentified high-altitude objects, has had such an impact on Americans.

Technology moves on

After the Powers incident, U.S. scientists and engineers at Lockheed's famous "Skunk Works" designed and built another generation of high-speed, high-altitude reconnaissance aircraft. The Lockheed SR-71would be christened the Blackbird. It would cruise at Mach 3+, more than three times the speed of sound, and it would provide all the overflight capabilities once promised by the U-2 and far more. It could literally outrun the surface-to-air missiles of its era.

The Blackbird had its first test flight in 1964 and dominated the category for a quarter century. But eventually both the U.S. and the Soviet Union and others were relying on unmanned aerial vehicles and satellites in orbit in space to provide surveillance of each other's military activities and movements without detection. One of the original 32 Blackbirds built now sits in dignified retirement at the new Smithsonian Air and Space Museum near Dulles Airport outside Washington, D.C.

China, too, has surveillance satellites taking pictures of the U.S., but some believe their technology in this regard may not be state of the art. That has been proposed as a potential explanation for their use of balloons to supplement their surveillance and data gathering.

Suspicions of foreign designs far back in diplomatic history

Even with two great oceans separating the U.S. from the rest of the world, Americans have long feared the designs of other nations. George Washington famously warned against "foreign entanglements" in his farewell address, and most of his successors in the presidency sought to keep such involvements as minimal as possible.

This was not, of course, always possible. As early as the administration of John Adams, the nation's second president, other nations were making every effort to enlist the aid of the fledgling republic or prevent its alliance with adversaries.

In 1798 the U.S. had its first real national scandal over three French diplomats who had code names corresponding to the last three letters in the alphabet. The so-called "XYZ Affair" came close to crashing the Adams administration and encouraged the rise of the first true "opposition party" in Congress.

Although the U.S. did not matter much in the global affairs of the 1800s, by the time of World War 1 the promise of American troops and armaments had the potential to decide the war. German submarine attacks on Atlantic shipping, including the passenger ship Lusitania, pushed American sentiment in one direction. But many German-Americans and Irish-Americans opposed entry into the war on the side of Britain.

As public opinion seemed unsettled early in 1917, a story emerged from British intelligence about a message supposedly intercepted between Germany and Mexico. Known as the "Zimmerman telegram," it described a plan by which Mexico would attack the U.S. if the Americans entered the European war against Germany. Mexico's reward would be the return of Texas, Arizona and New Mexico, which had once been part of Mexico. The story provoked outrage and contributed to a rising sense that war was inevitable, and indeed Congress declared war that April.

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