How was authoritarian rule challenged?

Internal opposition, popular resistance, impact of policies, and external threats.

A group of Munich university students (led by Hans and Sophie Scholl) who secretly distributed anti-Nazi leaflets from 1942; executed in 1943. An example of popular resistance in Nazi Germany (Europe).

Colonel Claus von Stauffenberg's failed attempt to assassinate Hitler using a bomb at his headquarters; Hitler survived, conspirators were executed. An example of internal opposition (army) in Nazi Germany.

A failed April 1961 invasion of Cuba by CIA-backed Cuban exiles, hoping to trigger an uprising against Castro; defeated within three days. An example of external threat in Cuba (Americas).

A trade ban imposed from 1960 that caused economic hardship but let Castro blame the US and rally nationalist support instead of collapsing his regime.

External military defeat — Allied invasion from west and east in 1944–45, ending in surrender in May 1945, not the internal 1944 bomb plot.

A person who openly disagrees with a government, often at personal risk.

An official ban on trade with a country, used as external pressure on a regime.

Nazi Germany: external invasion (1944–45) was decisive and ended the regime. Cuba: external pressure (Bay of Pigs, embargo) was absorbed and the regime survived for decades — external threats work best combined with internal weakness.

South Africa (Africa & Middle East) faced internal resistance AND external sanctions/boycotts together, which eventually forced negotiated change by 1994 — Cuba survived because internal opposition stayed weak despite similar external pressure.

A regime policy of violent repression in apartheid South Africa that turned international opinion against the regime — an example of a policy's impact fuelling external and internal pressure.

State explicitly to what extent the claim is true, using ≥2 examples from ≥2 different IB regions, rather than only describing examples without concluding.