Ambassador to Germany (2017–2020)
In September 2017, Trump nominated Grenell to become the United States ambassador to Germany. After a significant delay, the United States Senate confirmed Grenell 56 – 42 on April 26, 2018. Grenell was sworn in by Vice President Mike Pence on May 3, 2018, making him the highest-ranking openly gay U.S. ambassador. Grenell was also under consideration for the posts of U.S. ambassador to NATO and U.S. ambassador to the United Nations, the latter position being filled by Ambassador Kelly Craft.
Grenell presented his credentials to the president of Germany on May 8, 2018. Within hours of taking office, Grenell offended German diplomats and business leaders when he tweeted that "German companies doing business in Iran should wind down operations immediately". The tweet was widely perceived as a threat, with the Foreign Minister of Luxembourg, Jean Asselborn, commenting that "This man was accredited as ambassador only yesterday. To give German businesses such orders (…) that is just not how you can treat your allies". The leader of Germany's Social Democratic Party said that Grenell "does appear to need some tutoring" in the "fine art of diplomacy", while the Left Party urged the Merkel government to summon Grenell to explain his comments.
Grenell stirred controversy in June 2018 by telling Breitbart News, "I absolutely want to empower other conservatives throughout Europe, other leaders". This comment was described as a breach of diplomatic protocol and a breach of Article 41 of the Vienna Convention on Diplomatic Relations, which stipulates that ambassadors have a "duty not to interfere in the internal affairs of that State". Prominent German politicians called for Grenell's dismissal. Martin Schulz, former leader of the Social Democratic Party of Germany, said, "What this man is doing is unheard of in international diplomacy. If a German ambassador were to say in Washington that he is there to boost the Democrats, he would have been kicked out immediately."
Grenell was a regular contributor on Fox News's Tucker Carlson Tonight during the first few months of his ambassadorship in Germany. In November 2018, he appeared on the show and repeated his criticism of Angela Merkel's immigration policies. Grenell contrasted Merkel with the recently elected Chancellor of Austria Sebastian Kurz, who (according to Grenell) "won in a very big way" because of his strict stance on immigration. The magazine Der Spiegel called these remarks a "thinly veiled call for a change of government in Berlin". Grenell's perceived interference in German politics drew criticism from several high-ranking German politicians. In March 2019, Wolfgang Kubicki, Vice President of the Bundestag and deputy chairman of the Free Democratic Party, charged Grenell with acting "like a high commissioner of an occupying power" and called for Grenell to be expelled from Germany.
In December 2018, during the furor surrounding Der Spiegel writer Claas Relotius, who it turned out had been fabricating stories for years, Grenell wrote to the magazine complaining about an anti-American institutional bias, and asked for an independent investigation. In January 2019, Grenell told Handelsblatt that European companies participating in the construction of the Nord Stream 2 gas pipeline are "always in danger, because sanctions are always possible". U.S. administrations had long opposed the Russian-backed Nord Stream 2, a pipeline for delivering natural gas from Russia to Germany. Grenell also threatened to sanction German companies involved in the construction of the Nord Stream 2.
Der Spiegel published a profile of Grenell on January 11, 2019, using interviews with 30 "American and German diplomats, cabinet members, lawmakers, high-ranking officials, lobbyists and think tank experts". The magazine wrote that "almost all of these sources paint an unflattering portrait of the ambassador, one remarkably similar to Donald Trump, the man who sent him to Berlin. A majority of them describe Grenell as a vain, narcissistic person who dishes out aggressively, but can barely handle criticism." The profile claimed that Grenell was politically isolated in Berlin because of his alleged association with the far-right Alternative for Germany Party, causing the leaders of the mainstream German parties — including the Chancellor herself — to avoid contact with him; while Grenell had pressed German parliamentarians to invite him to their districts, most had declined. The sources claimed that Grenell knew little "about Germany and Europe, that he ignores most of the dossiers his colleagues at the embassy write for him, and that his knowledge of the subject matter is superficial".
In the fall of 2018, Grenell played a key diplomatic role in planning the arrest of Julian Assange by providing backchannel assurances to Ecuador that Assange would not face the death penalty in the United States. In February 2019, it was announced that Grenell was leading the Trump administration's newly formed effort to promote the decriminalization of homosexuality in nations in which homosexuality was illegal. In January 2020, Lev Parnas told The Daily Beast that he was told to ask Grenell for advance notice if the DOJ were to move to extradite indicted Ukrainian oligarch Dmytro Firtash. Among other actions as ambassador, Grenell pressured Germany to take a tougher stance against Iran and Hezbollah.
Following his appointment as Acting Director of National Intelligence, Grenell has said he would resign as ambassador once a full-time DNI was confirmed. On May 25, 2020, after John Ratcliffe was confirmed, Grenell confirmed he would resign as ambassador in the coming weeks. He formally resigned on June 1, 2020.