As the CEO of ExxonMobil, Tillerson has ties with President Vladimir Putin of Russia. They have been associates since Tillerson represented Exxon's interests in Russia, the world's largest producer of crude oil, during Russian President Boris Yeltsin's tenure. Tillerson was responsible for the development of a partnership between Exxon and state-owned oil company Rosneft and the ultimately unsuccessful attempt to acquire a stake in Yukos, owned by Mikhail Khodorkovsky, before the firm was nationalized after Khodorkovsky's arrest. John Hamre, the president and CEO of the Center for Strategic and International Studies, of which Tillerson is a board member, says Tillerson "has had more interactive time with Vladimir Putin than probably any other American, with the exception of Dr. Henry Kissinger".