It 's easy to fish out a little monsters from the cauldron of Polish politics but only the big fish are important.
It is a mistake to underestimate the influence of anti-German political movements such as Endecja, even though they were excluded from the Polish Government during the Sanacja period.
After Pilsudski seized power in 1926, he suppressed Endecja and other anti-German political elements. However, after he died in 1935, a power struggle broke out among his successors, in particular between Beck and Smigly-Rydz. Since Beck's aim was to preserve and continue Pilsudski's policy of friendship with Germany, Smigly-Rydz sought the support of anti-German elements outside the Sanacja regime such as Endecja, and began to adopt some of their policies.
Thus, by 1939, parts of the Sanacja regime had become almost as anti-German as Endecja, despite the efforts of Beck to maintain the "spirit of 28 January", the date of the 1934 Polish-German Declaration of Non-Aggression.
There can be no doubt that Smigly-Rydz was a big fish, and he had aligned himself to a large degree with the little monsters of Endecja.
For information on the threat of Polish invasion of German eastern territories (East Prussia and Silesia) in 1923, I suggest this book by Josef Korbel:
" Poland between East and West: Soviet and German Diplomacy toward Poland, 1919-1933" (Princeton, N.J., Princeton U.P., 1963)
As you probably know, Josef Korbel was the father of former US Secretary of State Madeleine Albright.
The book refers to Polish military threats toward Germany and Danzig at various times between 1920 and 1933.
These two books also detail Polish aggressiveness and arrogance toward Danzig, which was subjected to a crippling boycott:
Kimmich, Christoph M , "The Free city: Danzig and German Foreign Policy, 1919-1934" (New Haven, Yale U.P., 1968)
Tighe, Carl, "Gdansk : National Identity in the Polish-German Borderlands" ( London ; Winchester, Mass. : Pluto Press, c1990)
Note that none of the three books cited above is biassed against Poland and toward Germany.
No doubt Poland was economically and politically a shambles in 1923, after the assassination of President Narutowicz, but Germany was equally a shambles, suffering hyperinflation and threatened by uprisings from the extreme Left and extreme Right.
Poland's army was a lot bigger than Germany's, and it would have had the full support of France if it had invaded the German eastern territories. With French support, the Polish army could have invaded and occupied German territory, despite its political and economic troubles.
WM, I can understand that like most Poles you want to see your country as the innocent victim of the aggression of its evil neighbours. But you have to accept that in the inter-war period Poland was itself an aggressive and expansionist power, with parts of its ruling class, particularly the officer corps, infected by the arrogant szlachta spirit.
For example, Poland wanted to dissolve Czechoslovakia and annex Slovakia, thereby achieving a border with Hungary.