Ever since the modern U.S.Saudi relationship began in 1945, the United States has been willing to overlook many of the kingdom's more controversial aspects as long as it maintained oil production and supported U.S. national security policies. Since World War II, the two countries have been allied in opposition to Communism, in support of stable oil prices, stability in the oil fields and oil shipping of the Persian Gulf, and stability in the economies of Western countries where Saudis have invested. In particular the two countries were allies against the Soviets in Afghanistan and in the expulsion of Iraq from Kuwait in 1991. The two countries have been in disagreement with regard to the State of Israel, as well as the embargo of the U.S. and its allies by Saudi Arabia and other Middle East oil exporters during the 1973 oil crisis (which raised oil prices considerably), the 2003 U.S.-led invasion of Iraq (which Saudi Arabia opposed), aspects of the "War on Terror", and what many in the U.S. see as the pernicious influence of Saudi Arabia after the September 11 attacks. In recent years, particularly the Barack Obama administration, the relationship between the two countries became strained and witnessed major decline. However, the relationship was strengthened by President Donald Trump's trip to Saudi Arabia in May 2017, which was his first overseas trip after becoming President of the United States. The October 2018 assassination of Saudi dissident and "Washington Post" journalist Jamal Khashoggi in a Saudi consulate in Turkey caused a serious rift between the countries. The United States sanctioned some Saudi nationals and Congress unsuccessfully attempted to cut off U.S. weapons sales to Saudi related to the war in Yemen due to opposition from the Trump administration. Turkish authorities and U.S. intelligence agencies concluded the killing was done on the order of Mohammed bin Salman, the crown prince of Saudi Arabia.