Here's a look at Venezuela, an OPEC member state that has the largest proven reserves of oil in the coalition.
(from the CIA World Factbook)
Area: 912,050 sq km, about two times the size of California
Coups and attempted coups
Elections and campaigns
Energy and utilities
Henrique Capriles Radonski
Oil and gas industry
Unrest, conflicts and war
Business and industry sectors
Government and public administration
Political Figures - Intl
Government bodies and offices
Business, economy and trade
Banking, finance and investments
Financial markets and investing
Protests and demonstrations
Embargoes and sanctions
International relations and national security
International trade law
Trade and development
Trade regulation and policy
US federal government
Economy and economic indicators
Voters and voting
Continents and regions
Crime, law enforcement and corrections
Law and legal system
Population: 31,304,016 (July 2017 est.)
Median age: 28.3 years old
Ethnic Groups: Spanish, Italian, Portuguese, Arab, German, African and indigenous groups
Religion: Roman Catholic 96%, Protestant 2%, other 2%
GDP (purchasing power parity): $389.4 billion (2017 est.)
GDP per capita: $12,400 (2017 est.)
Unemployment: 26.4.5% (2017 est.)
Venezuela is located on the northern coast of South America, sharing a border with Colombia, Brazil and Guyana.
The country's formal name is the Bolivarian Republic of Venezuela.
Despite being one of the world's top oil-producing countries, more than 30% of Venezuelans live below the poverty line as of 2015.
1520s - First settlement by Spanish explorers.
July 5, 1811 - Venezuela declares its independence from Spain, leading to more than ten years of war for independence.
1821 - The Spanish Army is defeated and Venezuela becomes part of the Republic of Gran Colombia.
1829 - Venezuela breaks away from Gran Colombia to become an independent republic.
1958 - After decades of political instability and military rule, a coup leads to democratic reforms that culminate with a presidential election. Rómulo Betancourt is elected president.
February 1992 - A coup led by Hugo Chavez is defeated. Chavez spends two years in prison before the charges against him are dropped.
December 1998 - Chavez is elected president.
1999 - Chavez introduces a new constitution that extends his term and strengthens the executive branch while reducing the influence of National Assembly. Voters approve of the changes via a referendum.
July 30, 2000 - Chavez is re-elected.
April 2002 - Chavez is briefly ousted during a coup. He returns to power after two days of violent clashes.
December 2, 2002 - A national strike begins to protest against Chavez. The strike lasts more than two months and affects oil prices worldwide.
February 2, 2003 - Opposition leaders launch a petition drive, collecting signatures endorsing several demands including the immediate removal of Chavez.
June 3, 2004 - The National Electoral Council announces that the opposition has collected enough valid signatures to call for a referendum against Chavez.
August 15, 2004 - Initial results in the recall referendum show about 59% of Venezuelans voted to keep Chavez in office. The next day, observers led by former US President Jimmy Carter announce that they found no fraud in the recall election.
December 3, 2006 - Chavez wins re-election.
February 15, 2009 - A constitutional referendum passes allowing Chavez to run for another term in 2012.
May 24, 2011 - The United States imposes sanctions against seven companies, including the state-run oil company, for supporting Iran in the energy sector.
May 2012 - Chavez, battling cancer, appoints 10 people to a commission called the Council of State. The move prompts speculation about who will succeed him.
October 7, 2012 - Chavez is re-elected.
April 14, 2013 - Maduro narrowly wins the presidential election, with 50.8% of the vote, defeating opposition candidate Henrique Capriles.
September 30, 2013 - Maduro announces on state-run TV that he is expelling three US diplomats. He claims they were involved in acts to destabilize the country.
February 12, 2014 - Protests are held as the economy sputters and crime increases. Some demonstrations turn violent. At least three protestors die amid the unrest.
February 18, 2014 - Opposition leader Leopoldo López is arrested. He is charged with conspiracy and murder in connection with the demonstrations. He is later convicted and sentenced to more than 13 years in prison.
December 18, 2014 - The Venezuela Defense of Human Rights and Civil Society Act is signed into law by US President Barack Obama. The measure directs the United States to impose sanctions against Venezuelan officials who engage in human rights abuses.
February 20, 2015 - The mayor of Caracas is arrested and accused of being involved in a plot to overthrow the government. The opposition says the mayor's arrest is an attempt to divert attention from the country's economic woes.
March 9, 2015 - Obama issues an executive order meant to address the human rights crisis in Venezuela, with sanctions against seven individuals.
December 6, 2015 - Venezuela's opposition party wins the majority of seats in elections to the National Assembly, a repudiation of Maduro. It is the first major shift in power in the legislative branch since Chavez took office in 1999.
January 15, 2016 - Maduro declares a state of "economic emergency." The country's economic issues are rooted in falling oil prices, plummeting currency rates, power struggles within the government, the looming possibility of default and ongoing food shortages.
March 4, 2016 - Obama renews sanctions against Venezuela, declaring that the situation hasn't improved since his last executive order.
March 9, 2016 - In response to the sanctions, Maduro announces he's recalling Maximilien Arvelaiz, Venezuela's top diplomat in Washington.
August 1, 2016 - The government certifies a petition to begin the process of recalling Maduro. A top election official calls for an investigation into irregularities on the signature list.
October 2016 - The recall referendum to oust Maduro is halted amid allegations of voter fraud. Opposition lawmakers meet for a special session to discuss the possibility of impeaching Maduro. Pro-government protestors break into the assembly hall to disrupt the meeting.
March 29, 2017 - The Supreme Court strips the National Assembly of power. Opposition leaders say that the move is comparable to a coup. After several days of protests, the court reverses its ruling.
April 7, 2017 - Capriles announces via tweet that the government has barred him from holding public office for 15 years.
April 17, 2017 - Maduro orders armed forces into the streets following weeks of deadly, anti-government protests.
April 20-21, 2017 - At least 13 people are killed in a single 24-hour period as protests continue.
May 1, 2017 - Maduro announces that he has signed an executive order paving the way for changes in the constitution that will reshape the legislature and redefine his executive powers.
June 27, 2017 - A stolen police helicopter, allegedly piloted by an officer from Venezuela's investigative police force, circles around several high-profile buildings in Caracas, including the Ministry of the Interior and the Supreme Court. Photos show an occupant holding a banner that says, "Article 350 libertad," referring to an article in the Venezuelan constitution that allows citizens to oppose the government should it subvert democratic principles.
July 5, 2017 - On the anniversary of the county's independence, Maduro supporters storm the National Assembly and attack opposition lawmakers. At least seven legislative employees and five lawmakers are injured.
July 16, 2017 - Nearly 7.2 million voters participate in a non-binding referendum organized by the country's opposition parties. More than 98% of voters reject Maduro's proposed constitutional changes. The government condemns the referendum as illegal and calls for a July 30 vote to elect a special assembly to rewrite the 1999 constitution.
July 26, 2017 - Steve Mnuchin, the Treasury Secretary for US President Donald Trump, announces sanctions on 13 government and military officials tied to Maduro. Mexico and Colombia follow with sanctions on the same individuals.
July 30, 2017 - An election is held to replace the National Assembly with a new pro-Maduro legislative body called the National Constituent Assembly. Amid clashes between police and protestors, at least six people are killed. Although Maduro claims victory, opposition leaders say the vote is fraudulent.
July 31, 2017 - Mnuchin announces that all of Maduro's assets that are subject to US jurisdiction will be frozen and all US citizens are barred from dealing with him.
August 2, 2017 - The CEO of the company that provided technology for the July 30 election says there is a discrepancy of at least one million votes. A spokesman for the government's election council denies that any manipulation took place. During an interview with CNN en Español, the attorney general says she has initiated an investigation into potential voter fraud.
August 5, 2017 - The Constituent Assembly holds its first session and issues its first order of business: firing the attorney general who is investigating allegations of voter fraud. A Maduro ally is sworn in as the interim attorney general.
February 8, 2018 - A prosecutor from the International Criminal Court says a preliminary investigation will examine allegations of excessive force and other abuses by the government during anti-regime protests dating back to 2017.
May 20, 2018 - During an election denounced by opposition leaders and the international community, Maduro wins another six-year term. Voter turnout falls to 46%, down from an 80% participation rate in 2013.
August 4, 2018 - Several drones armed with explosives fly towards Maduro in an apparent assassination attempt during a military parade. The next day, the interior minister announces that six people have been arrested in connection with the attack. Maduro is not injured.
August 18, 2018 - Peru and Ecuador announce new restrictions on migration, as Venezuelans try to flee to neighboring countries. A mob of Brazilians destroys a migrant camp and several Venezuelans are attacked after a shop in a border city is robbed, according to Brazil's state news service.
September 8, 2018 - A report is published in the New York Times detailing secret meetings between US officials and Venezuelan military officers planning a coup against Maduro. CNN confirms the report, which describes a series of meetings over the course of a year. Ultimately, the US government decided not to back the coup.