Final answer:
The primary opposition leader was among those freed when the new regime declared an amnesty for political prisoners, a move often seen in transitional periods of government as a means of reconciliation and reform.
Step-by-step explanation:
The primary opposition leader was among those freed when the new regime declared an amnesty for political prisoners. Amnesty is often granted after periods of political unrest or regime changes when the new government wishes to signal a break from the past and to work towards national reconciliation. Such amnesties can be seen in a variety of historical and modern contexts, from the Manifesto of the Central Committee of the Social Democrats in 1917 laying out a support for a government that promised reforms including amnesty, to the release of Nobel Peace Prize winner Aung San Suu Kyi from house arrest, symbolizing a shift towards more open and democratic governance in Myanmar.
Amnesties may follow large protests and uprisings against previous regimes, like in the Eastern Bloc countries, where protests led to political thaws, or in situations where resistance to oppression has been a long struggle, such as H_o Chi Minh's opposition to French domination, eventually leading to Vietnam's independence. It signifies a pivotal moment wherein a government acknowledges past conflicts and moves towards establishing a more inclusive future for all its citizens, sometimes as a part of broader reforms demanded by the populace.