Suppose you were in charge of your country's defense, and an aircraft from an unfriendly nation came into your airspace. What would you do? Would you send up your fighter planes to chase the aircraft away? Would you ask the pilot of the plane what he was doing? Would you force the intruding plane to land? Or would you shoot the plane down?
All these questions come rushing to the surface after the world's outcry over the Soviet Union's attack on an unarmed South Korean passenger plane. All 269 people aboard were killed when the plane was shot down Aug. 31 Eastern daylight time after straying into Soviet airspace.
Many countries are outraged that the Soviets could do such a thing. At first, the Soviets wouldn't admit they had done anything wrong. Their version was that the plane was flying without lights and ignored all messages. They then went on to assert that it must have been a spy plane. The United States government was angry not just because a civilian plane with innocent people aboard had been shot down. It was also furious that the Soviets were not telling the truth. A record of the messages from two Soviet airplanes back to the Soviet ground station shows that the Korean plane's navigation lights were on and that the target had been destroyed. Several days after the incident the Soviet Union finally admitted shooting down the plane while still insisting it was a spy plane.
The Americans don't think it's possible for the Soviets to mistake a civilian plane for a spy plane, particularly since the 747 Korean airliner that was shot down has a silhouette unlike any other plane in the world.
Moreover, commercial aircraft from the Soviet Union and Cuba have flown over sensitive US military installations before, but they haven't been shot out of the sky for it.
Probably we will never know why the Soviets did what they did, since the Soviet Union is a very secret society. It is also a society that has great fears about its own security. Perhaps more so than other countries.
One explanation, although not an excuse for its recent actions, could be its history. Unlike the US, which has never been attacked, the Soviet Union has been threatened in the past by foreign forces on its soil. This happened not only with the Germans in World War I and again in World War II, but on several other occasions as well.
In June, 1812 - more than 170 years ago - Napoleon's great army numbering some 453,000 men crossed the borders of Russia. The Russians retreated until Napoleon finally engaged them in a bloody battle at Borodino on Sept. 7, 1812. A week later the French entered Moscow, which the Russians had abandoned. A biting cold winter that came sooner than expected left Napoleon's force deep in Russian territory. He was forced to retreat. In the end only 10,000 of his troops made it back.
But the memory of French troops penetrating so deep into Russian territory made a lasting impression on the Russians. The Russians were again reminded of invasion when in World War II another enemy - this time Hitler's Nazi Germany - invaded their country.
There were several parallels with the 1812 invasion. The Germans, like Napoleon's Army years before it, were also forced eventually to retreat, also in biting cold weather.
In both instances, the Russians practiced what is known as the ''scorched earth'' policy. This meant that they kept on retreating before their enemy and devastating the countryside so that no food or supplies would be left for the enemy. The result was that for both the advancing armies of France, in 1812, and Germany, in World War II, the countryside was laid waste and there was nothing to eat. As these two armies at quite different periods in history went deeper and deeper into Russia, they became more and more isolated as they moved further from their main bases and supply lines.
Although both armies also had finally to give up their conquest of Russia and retreat back to their own lands, the Russian losses, particularly in World War I and World War II, were staggering. It is estimated that the USSR lost at least 18 million in World War II alone. This included 11 million soldiers and 7 million civilians.
Historians say it is this background that makes the Russians so suspicious of foreigners and so concerned about their security.
While Western leaders today may understand why the Soviets act the way they do, they do not excuse the harsh tactics they use either to keep control in their own country or to keep foreigners out.
The shooting down of a South Korean plane with innocent victims aboard has been condemned as uncivilized behavior. To show his disapproval, US President Reagan has demanded that the Soviets pay a price for shooting down the plane. He has announced measures that would limit the amount of exchanges the Soviets have with the Americans. He is also pushing to restrict the amount of flying Soviet civilian aircraft can do in the West. President Reagan has also called for the Soviet Union to pay money to the relatives of those killed when the plane was shot down. Other nations are also thinking of what action they may take against the Soviets.