If I correctly recall my history, and William L. Shirer’s The Rise and Fall of the Third Reich, there are uncomfortable echoes of 1939 Poland in these current events. ‘Unidentified armed men’, indeed.
A work which everyone should read - Hugh Trevor-Roper
However, there was one exception: in the night of 25–6 August, a German sabotage group which had not heard anything about a delay of the invasion made an attack on the Jablunkov Pass and Mosty railway station in Silesia. On the morning of 26 August, this group was repelled by Polish troops. The German side described all this as an incident "caused by an insane individual".
On 29 August, the German government stated that it aimed not only for the restoration of Danzig but also the Polish Corridor (which had not previously been part of Hitler’s demands) in addition to the safeguarding of the German minority in Poland (my italics). It said that they were willing to commence negotiations, but indicated that a Polish representative with the power to sign an agreement had to arrive in Berlin the next day while in the meantime it would draw up a set of proposals. Needless to say, it was engineered that this ultimatum was impossible to meet and when no such representative could reach Berlin in time, it was then broadcast that Poland had rejected Germany's offer, and negotiations with Poland came to an end. Hitler issued orders for the invasion to commence soon afterwards.
That same day, German saboteurs planted a bomb at the railway station in Tarnów and killed 21 passengers, leaving 35 wounded.
During the night of 31 August, a false flag attack on the radio station, was staged near the border city of Gleiwitz by German units posing as Polish troops (my italics) in Upper Silesia as part of the wider operation… On 31 August 1939, Hitler ordered hostilities against Poland to start at 4:45 the next morning. Because of these political vacillations over the previous week, Poland managed to mobilize only 70% of its planned forces, and many units were still forming or moving to their designated frontline positions when the blitzkrieg began. [Memory jogged by Wikipedia.]
2014. There is still no official confirmation of who the armed men surrounding key areas in Crimea really are. They wear uniforms without insignia and drive unidentified vehicles. Some say they are locals organising themselves into a self-defence unit against the Ukrainian uprising…
Uncomfortable echoes indeed.