If Smaug appeared over Germany in 1940, could German forces stop him without a nuclear weapon?
Short answerYes; conventional anti-aircraft guns could exploit the missing scale on his underside, although hitting that weak point would be difficult.
NotesSmaug's missing scale gives the fictional target a weakness that conventional anti-aircraft fire could exploit. A shell or projectile would have to reach that exposed area, so the proposed solution depends on penetration and accurate fire. An 88 mm gun is suggested first, followed by massed smaller-calibre weapons. A warship carrying 40 mm guns is preferred over German 37 mm weapons or the 88 mm in the final assessment. Smaug's manoeuvrability makes hitting the small vulnerability difficult, and an attempt to capture him could expose the defenders to further losses.