Is this the end of Europe? For years it dined off the deal of a lifetime: the US guaranteed its security if it acted as an outpost for American troops. Now a reckoning has come.
Nato is dying, warns new German leader
"Mission impossible": How one former French ambassador to the US described Macron's task of persuading Trump to support Ukraine in their meeting on Monday. Glossary
Emmanuel Macron - The current president of France, nicknamed "Jupiter" after the chief of the Roman deities for his top-down manner of governance.
UN - United Nations. An intergovernmental organisation based in New York that aims to maintain international peace and security.
Friedrich Merz - A German politician and member of the Christian Democratic Union. He is expected to become the next leader after the recent German elections.
Nato - The North Atlantic Treaty Organisation was founded in 1949 to unite Western democracies in Europe and North America against the perceived growing threat of the USSR. It now has 31 members.
Far right - A range of ideologies that emphasise social order, racial purity, and the elimination of opponents.
Ally - A country that has agreed to support another one.
Isolationism - Throughout American history, some presidents (like George Bush and Barack Obama) have promoted co-operation and intervention in world affairs. In contrast, Trump talks about putting Americans first and not being restricted by international treaties.
Welfare states - A form of government in which the state protects the wellbeing of its citizens, through benefits such as pensions and health services.
Holocaust - The murder of six million Jewish people in Europe by Nazi Germany. Members of other minority groups were also killed.
USSR - The United Socialist Soviet Republic, the USA’s main rival in the Cold War before it collapsed and broke up into a number of smaller states in 1991.
Faustian pact - A bargain in which someone trades something of moral significance, such as personal values, for something material. The term comes from Faust, a German folklore figure who gives his soul to an evil spirit in return for magical powers.
Autonomy - The right to make your own decisions.
Georgia - A state in the southern USA. Also a country at the intersection of Europe and Asia.
EU - European Union. An economic and political union of 27 countries.
International Criminal Court - An international tribunal that has jurisdiction to prosecute individuals for committing genocide, crimes against humanity and war crimes.
Benjamin Netanyahu - The prime minister of Israel.