Land of southern Luxembourg. This last route, however, is by far the longest for any attack aimed at reaching the Meuse River.
The geography of the Ardennes leads inevitably to the channelization of large troop movements east to west, will tend to force larger units to "pile up" on each other, and restricts freedom of maneuver once the direction of attack and order of battle are fixed. To a marked degree the military problem posed by the terrain is that of movement control rather than maneuver in the classic sense. For the smaller tactical units, the chopped-up nature of the ground plus the peculiar timber formations in which dense wood lots are interspersed with natural or manmade clearings, indicates the development of a series of small, semiindependent engagements once the larger battle is joined. Movement cross-country is limited, even in good weather; movement along the narrow valley floors may be blocked there or in the villages at points of descent and ascent. The backbone of the ridges sometimes offers good observation in the immediate area for detecting movement on the roads which climb the hills and plateaus. Locally, however, the gunner or fighter pilot will find many blind spots formed by the thick tree cover or the deep draws and ravines; the ability of high-angle fire to beat reverse slopes, which really are sheer, steep walls, is limited.
What the German planners saw in 1944 was this: the Ardennes could be traversed by large forces even when these were heavily mechanized. An attack from east to west across the massif would encounter initially the greatest obstacles of terrain, but these obstacles would decrease in number as an advance neared the Meuse. In 1914 and 1940 the German armies moving across the Ardennes had no reason to anticipate strong opposition on the ground until the Meuse had been reached and the tortuous defiles left behind. In 1940 the only German concern had been that the French air force would catch the armored columns at the crossings of the Sauer and Our Rivers. In both these earlier campaigns the Germans had thrown a protective screen clear to the Meuse within twenty-four hours after the advance began; the initial objectives of these screening movements have more than historic significance: Bastogne, St. Vith, Arlon, Malmedy, La Roche, and the bridges over the Ourthe River.
The ground offered the defender three natural defense positions east of the Meuse, although none of these constituted an impassable barrier to the attacker: (1) a covering line echeloned to the southeast between Liege and the Moselle, this pegged on the Hohes Venn, the rugged zone around Malmedy and St. Vith, and the boxed-in course of the Our and Sauer Rivers; (2) the Ourthe River line; and (3) an intermediate position, shorter in length, based on the plateau at Bastogne and extending along a chain of ridges to Neufchateau.
There remains a word to be said about the climate of the Ardennes and Eifel. This is mountainous country, with much rainfall, deep snows in winter, and raw, harsh winds sweeping across the plateaus. The heaviest rains come in November and December. The mists are frequent and heavy, lasting well into late morning before they break. Precise predictions by the military meteorologist, however, are difficult because the Ardennes lies directly on the boundary between the