Three years after a U.S. drone strike in Yemen killed two civilians attending a wedding, a German court on Wednesday ruled against a member of the victims’ family in a case that challenges international support for the so-called “War on Terror.”

Faisal bin Ali Jaber was granted permission to appeal the court’s decision after judges rejected his constitutional claim against Germany, filed last October following the deaths of Jaber’s nephew and brother-in-law, killed in a U.S. drone strike on August 29, 2012 in the village of Khashamir.

The claim was filed after revelations that Ramstein Air Base, situated in southwest Germany but operated by the U.S. Air Force, is “crucial to facilitating American covert drone strikes in Yemen,” according to legal charity Reprieve. Jaber is represented by Reprieve and the European Center for Human Rights.

Jaber could not testify in person because travel restrictions in Yemen—implemented over the Saudi Arabia-led military assault against Houthi rebels—prevented him from leaving the country. He had his statement read before the court on Wednesday.

President Barack Obama and German officials previously denied that Germany was involved in drone operations. However, a top-secret intelligence document leaked earlier this year confirmed that Ramstein “is the site of a satellite relay station that enables drone operators in the American Southwest to communicate with their remote aircraft in Yemen, Somalia, Afghanistan and other targeted countries,” as written by The Intercept, which published a report on the document in April.

The 2012 strike prompted protests in Yemen, particularly as one of the men killed, Salim bin Ali Jaber, was known to be a vocal opponent of al Qaeda, the purported target of the attack.

Observers said before the ruling that the case could have set a precedent for international governments participating in the U.S. drone strike campaign. The judges on Wednesday only conceded that it is “plausible” the Ramstein base is a crucial part of the U.S. drone strike operation in Yemen.