Some of Ukraine's tactics in its surprise attack into Russia's Kursk region resembled German methods in the Battle of the Bulge.ROMAN PILIPEY/AFP via Getty ImagesSome observers have argued surprise attacks are nearly impossible due to wide surveillance.Ukraine's Kursk invasion caught Russia by surprise and followed time-honored tactics.The question for Ukraine is whether Kursk will fare better than Germany's Battle of the Bulge.When Ukraine unleashed its Kursk offensive in August, it wasn't just the Russians who were surprised.Some experts had argued that large-scale attacks were no longer possible in modern warfare.