$   Growing tensions between Germany and Russia in the pre-war period resulted in fortification of East$
$Prussia.  Fortifications were build along main roads and isthmuses between masurian lakes.$
$   Area between Varta and Oder rivers - the shortest way from Poland towards Berlin was also fortified.$
$Germans anticipated, that Polish Army would strike in case of Wehrmacht engagement in France. Similar$
$line of fortifications was built along the border with France (Siegfried Line). That line was intended$
$to suppress the potential French advance in case France would fulfill its obligations to help Poland$
$attacked by Germans.  Siegfried's line wasn't attacked, although Wehrmacht forces attacked Poland with$
$almost all available resources at their disposal, French Army did nothing, limiting itself to bombing$
$Germans with leaflets.$
