President-elect Donald Trump has tapped Rex Tillerson, the chief executive of ExxonMobil, to be his Secretary of State.

Tillerson has no formal foreign policy experience but in a statement released on Dec. 13, Trump praised him saying, “Rex Tillerson’s career is the embodiment of the American dream.

“Through hard work, dedication and smart deal making, Rex rose through the ranks to become CEO of ExxonMobil, one of the world’s largest and most respected companies. His tenacity, broad experience and deep understanding of geopolitics make him an excellent choice for Secretary of State.”

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Although Trump’s selection has alarmed both Democrats and Republicans because of Tillerson’s close relationship with Russia, former Secretary of State Condoleezza Rice has called the President-elect’s decision an “excellent choice.”

She wrote in a Facebook post, “Rex Tillerson is an excellent choice for Secretary of State. He will bring to the post remarkable and broad international experience; a deep understanding of the global economy; and a belief in America’s special role in the world.”

Here are five things to know about Rex Tillerson.

1 Tillerson has no formal foreign policy experience, but he does know a thing or two about diplomacy.

Rex Tillerson has worked at ExxonMobil for 41 years, where he started as a production engineer and then went on to buy and sell oil in various parts of the world. With this job, he has worked closely with leaders of numerous countries, including Nigeria, Qatar and Sudan.

Despite this, it’s still important to note that being a CEO and Secretary of State are two very different roles. As the Secretary of State, Tillerson will have to deal with human rights issues, strengthening NATO alliances and settling a peace deal between Israel and Palestine. Not only that, but without former political experience, many of his official stances on political issues like climate change are not known.

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2 Tillerson has close ties with Russia.

Rex Tillerson has had a relationship with Russia and Vladimir Putin, the president of Russia, for over two decades. In 2013, he was even awarded Russia’s Order of Friendship after signing deals with Rosneft, a state-owned Russian oil company. The partnership began a drilling program in Kara Sea and there Exxon found and agreed to explore shale oil areas of West Siberia and the Black Sea.

However, after the U.S. imposed economic sanctions on Russia over the Ukraine conflict, the partnership halted. Since then, he has advocated for the lifting of sanctions against Russia, which is a potential conflict of interest. “Mr. Tillerson’s stake in Russia’s energy industry could create a very blurry line between his interests as an oilman and his role as America’s leading diplomat,” wrote The New York Times.

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3 Tillerson supports a carbon tax, but believes the world will continue to use fossil fuels regardless.

ExxonMobile is one of the largest companies in the oil industry, making it the target of many environmentalists. To respond, the oil giant has said it supports carbon tax, but The Wall Street Journal has pointed out that Tillerson hasn’t actively pushed for it.

The Exxon CEO, however, frequently cites what he said in a 2009 speech, “As a businessman it is hard to speak favorably about any new tax. But a carbon tax strikes me as a more direct … a more transparent … and a more effective approach.”

Nevertheless, Tillerson also believes that fossil fuels will still be used, despite the country’s efforts to mitigate it. “The world is going to have to continue using fossil fuels whether they like it or not,” Tillerson said earlier this year.

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4 Tillerson is a big supporter of Common Core.

The Common Core initiative is a set of math and English standards that were initially created in the hope that the U.S. would adopt them to allow for cross-state comparisons of student performance. But, the President-elect has been a vocal opponent of the core and has vowed to “get rid of it.” Trump’s choice for education secretary, Betsy DeVos, has also pledged to end it.

However, in an op-ed piece published in Business Roundtable, Tillerson argues that “as a nation, we must unite in recognizing the mounting evidence that the U.S. is falling behind international competitors in producing students ready for 21st-century jobs.” According to him, Common Core can help reverse America’s education decline to help prepare young people “to compete in today’s dynamic global economy.”

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5 Tillerson has pushed for openly gay youth to be allowed to join the boy scouts.

Outside of Exxon, Tillerson has continuously supported the Boy Scouts of America and served as president of the organization from 2010 to 2012. During his tenure, he advocated for the right of openly gay youth to join the Boy Scouts. Although the ban on gay adult troop leaders wasn’t lifted until July 2015, he has been called “instrumental” to the changes made in the organization.

“He was instrumental in leading the organization through an important period of growth and development, while upholding the long-standing traditions of character and good citizenship that are essential to Scouting’s mission,” the Boy Scouts recently said in a statement.

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