Hitler invaded and annexed Austria on March 12, 1938. He told the country that it had to be done because Germans in Austria were in danger.

Between October 1 and October 10, 1938, German troops invaded the Sudetenland, the north-western border areas of Czechoslovakia. The pretext was that 3.5 million ethnic Germans suffered privations at the hands of the Czechs. Once in the country, he quickly advanced further and on March 15, 1939, Hitler moved into the balance of Czechoslovakia and the country ceased to exist.

Soon after, on September 1, 1939, Germany invaded Poland, and that date was the official start of World War II. The pretext, again, was that there were Germans being discriminated against by the Poles. By that time, however, Hitler really didn’t worry so much about his rationalizations. He believed he needed Lebensraum (living space) and Poland was populated by the Slavs, who were, according to him, an inferior race and deserved being enslaved.

In March 2014, Russian troops invade the Crimea, a territory of the Ukraine. The pretext: There are ethnic Russians in the Ukraine who are being mistreated and abused by the Ukrainians.

Claiming this pretext seems like a really effective way to convince ones own country to support an invasion of a neighboring country. Putin is a good student of history.