A British Heligoland would reshape Germany's western strategy

What if Britain retook Heligoland under the Treaty of Versailles?

Britain would probably establish an air base there, creating a forward threat that could influence German plans toward the Low Countries.

British control of Heligoland would matter most as a forward operating base. Supplying and defending the island would be demanding, but modern fighters stationed there could threaten German freedom of action in the North Sea. That pressure would strengthen German incentives to control nearby continental territory and airspace.