A firewall is a wall designed to prevent a fire from spreading from one building to another. In German politics, the term "firewall" serves as a metaphor for a strict boundary drawn against parties regarded as extremist. Just as a firewall is intended to protect buildings from fire, the "political firewall" is intended to safeguard democracy.

Whether the Alternative for Germany (AfD) is in fact a party that is hostile to democracy has not yet been determined by the courts. While Germany's domestic intelligence agency, the Federal Office for the Protection of the Constitution, has classified individual AfD state associations as "confirmed right-wing extremist," the question of whether the party as a whole is acting against the German constitution would have to be decided by the Federal Constitutional Court in proceedings to ban the party.

Calls for an AfD ban have been made repeatedly, but no formal application has been filed to date.

How much of a neo-Nazi party is the German AfD? To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video

Chancellor Merz is growing tired of the term 'firewall'