How did the berlin blockade impact the cold war?
it stopped the reunification of germany under pro-american government.
it allowed the soviet union to retain control over most of eastern europe.
it convinced the united states that it must stand firm against communist expansion.
it prevented the soviet union from placing missiles within striking range of western europe.

It convinced the United States that it must stand firm against communist expansion.

Explanation:

The Berlin Blockade was a significant crisis during the Cold War. During the blockade, the Soviet Union blocked the Allies' access to the areas of Berlin that were under Western control. The Soviets also offered to drop the blockade if the Western Allies withdrew the Deutsche Mark from West Berlin. The Berlin blockade was significant because it highlighted the fact that there were two competing and mutually exclusive ideologies and economic visions in Europe. This convinced the United States of the need to stand firm against communist expansion.

answer: secession

secession, as it applies to the outbreak of the american civil war, comprises the series of events that began on december 20, 1860, and extended through june 8 of the next year when eleven states in the lower and upper south severed their ties with the union. the first seven seceding states of the lower south set up a provisional government at montgomery, alabama. after hostilities began at fort sumter in charleston harbor on april 12, 1861, the border states of virginia, arkansas, tennessee, and north carolina joined the new government, which then moved its capital to richmond, virginia. the union was thus divided approximately on geographic lines. twenty-one northern and border states retained the style and title of the united states, while the eleven slave states adopted the nomenclature of the confederate states of america.

explanation: