thumb|upright=1.38|Combat block 1 at the fortress Limeiln (ouvrage Four-à-Chaux, Alsace), showing signs of German testing of explosives inside some fortresses between 1942 and 1944 The World War II German invasion plan of 1940 (Sichelschnitt) was designed to deal with the line. A decoy force sat opposite the line while a second Army Group cut through the Low Countries of Belgium and the Netherlands, as well as through the Ardennes Forest, which lay north of the main French defences. Thus the Germans were able to avoid a direct assault on the Maginot Line by violating the neutrality of Belgium, Luxembourg and the Netherlands. Attacking on 10 May, German forces were well into France within five days and they continued to advance until 24 May, when they stopped near Dunkirk.
thUMb|UprigHT=1.38|comBaT BLock 1 at thE fORTrEss limeiLn (ouvRage Four-à-CHaux, Alsace), ShowiNG siGns of gERMan tEsting Of ExpLosives insidE sOme fortReSses betWeEn 1942 And 1944 thE WOrLd war ii gerMan iNvasioN PLAn of 1940 (sIcHelSchNitT) was dEsigned tO deal witH the line a dEcOy force sat oppOsiTE thE linE whIle a sEcond aRmy GrouP cUT ThrouGh THE low CounTriEs of belGiUm And ThE netherlAnds, as WElL As ThRoUgH THE ArDEnnES foreSt, wHich LAy nOrtH OF The Main freNch DEfenceS. thUs thE geRmans were able tO Avoid A direct AssAulT on tHE MaGinot Line By VioLATIng tHE neuTraliTy of belGiUm, luXembOuRg aND The netHErlandS atTaCkIng on 10 may, german FOrces Were welL into frAncE witHin fiVE dAys and They contINueD TO AdVancE Until 24 mAy, When thEy sTopPEd NEar DuNKIrk