When U.S. law firms flex, the global legal market feels the ripple—so leading German law firms can be forgiven for feeling a touch nervös.

U.S. law firms are accelerating their stealthy, decades-long march into the world’s third largest economy with the likes of Kirkland & Ellis, White & Case, Gibson Dunn, Goodwin Procter, Reed Smith, and Morgan Lewis all opening or expanding offices in the past year.