Estonian Prime Minister Kaja Kallas has, as expected, submitted her resignation in order to serve as the European Union’s top diplomat. Kallas informed the parliament in Tallinn of her decision on Monday and submitted her letter of resignation to President Alar Karis. Under to the Estonian constitution, Kallas’ move automatically leads to the resignation of the entire government of the Baltic EU and NATO member state. Until a new Cabinet of ministers is confirmed, however, it will remain in office on a caretaker basis. Kallas, 47, was nominated by EU leaders in June to become the bloc’s foreig…