<Dd> 16: Philippe Pétain becomes premier of France upon the resignation of Reynaud's government . The French sloop La Curieuse forced the Italian submarine Provano to surface and then sank it by ramming . Soviet Union gives eight - hour ultimatum to Latvia and Estonia to surrender . </Dd> <Dd> 17: Sinking of liner RMS Lancastria off St Nazaire while being used as a British troopship--at least 3,000 are killed in Britain's worst maritime disaster . Soviet troops enter Latvia and Estonia . </Dd> <Dd> 18: General De Gaulle forms the Comité français de la Libération nationale, a French government in exile; Estonia, Latvia and Lithuania are occupied by the Soviet Union . </Dd> <Dd> 20: The French seek an armistice with the Italians . </Dd>

The only democratic country in europe left to fight germany by july 1940