According to SPIEGEL research, United States intelligence agencies have not only targeted Chancellor Angela Merkel’s cellphone, but they have also used the American Embassy in Berlin as a listening station. The revelations now pose a serious threat to German-American relations.

It’s a prime site, a diplomat’s dream. Is there any better location for an embassy than Berlin’s Pariser Platz? It’s just a few paces from here to the Reichstag. When the American ambassador steps out the door, he looks directly onto the Brandenburg Gate.

When the United States moved into the massive embassy building in 2008, it threw a huge party. Over 4,500 guests were invited. Former President George H. W. Bush cut the red-white-and-blue ribbon. ChancellorAngela Merkeloffered warm words for the occasion. Since then, when the US ambassador receives high-ranking visitors, they often take a stroll out to the roof terrace, which offers a breathtaking view of…