Short answers, pulled from the story.
A neutral country is a sovereign state that refrains from joining either side of a conflict and adheres to the Law of Neutrality under international law. The rights and duties of a neutral power are defined in sections 5 and 13 of the Hague Convention of 1907. Permanently neutral powers are bound by international treaty or their own declaration to remain neutral in all future wars.
Armed neutrality is the posture of a state that takes no military alliance with any side in a war but stands ready to defend itself by force against any belligerent incursion. Switzerland and Sweden are the most recognized examples, both having maintained armed neutrality through World War I and World War II. Switzerland has not been at war internationally since 1815; Sweden since 1814, until it joined NATO in 2024.
The First League of Armed Neutrality was an alliance of minor naval powers organized in 1780 by Catherine II of Russia to prevent the Royal Navy from inspecting neutral ships during the American Revolutionary War. Americans viewed the league as a sign of Russian friendship and sympathy. Political scientists regard it as the first historical example of armed neutrality, though scholars like Carl Kulsrud argue the concept appeared even earlier.
Most nominally neutral countries made significant concessions to one or both sides during World War II. Ireland secretly shared D-Day weather data with the Allies and allowed British aircraft to use the Donegal Corridor. Sweden permitted the 163rd German Infantry Division to transit its rail network to Finland. Portugal sold tungsten to Germany while providing naval bases to the Allies. Only Andorra, Ireland, Portugal, Spain, Sweden, Switzerland with Liechtenstein, and Vatican City remained neutral to the end among the European states closest to the fighting.
Since the Lisbon Treaty, EU members are bound by Article 42.7 of the Treaty on European Union, which requires them to assist a fellow member under armed aggression, though neutral states may respond with non-military aid. Three EU members still describe themselves as neutral: Austria, Ireland, and Malta. Ireland's constitution separately prohibits participation in a common defense, and Malta was the only neutral EU state to remain outside Permanent Structured Cooperation as of December 2017.
Switzerland joined the United Nations in 2002, having refused membership for decades in strict defense of its armed neutrality. Despite this long-standing position, Switzerland's Armed Forces participated in the U.S.-led War in Afghanistan, which the Swiss Broadcasting Corporation described as the nation's first military deployment since 1815.