Unternehmen Herbstnebel ("Operation Autumn Mist") was an offensive planned by German Field Marshal Walter Model and his Army Group B operational staff in late 1944 during World War II. It envisaged a German Army attack targeting the Allied forces in eastern Belgium and Luxembourg, east of the Meuse River.

Based on that paragraph can we conclude that this sentence is true?
Unternehmen Herbstnebel was successful.
It's impossible to say