Why was the decline of the Soviet Union an important factor in the fall of communist governments in Eastern Europe?
O A. It left the Soviet Union too weak to provide military support to its
communist allies.
B. It led desperate Soviet leaders to invade Eastern Europe to acquire
new territories.
O C. It gave Western European democracies economic control over
Eastern European states.
O D. It forced communist leaders in Eastern Europe to rely on the
United States for support.

union blockade

explanation:

the union blockade in the american civil war was a naval strategy by the united states to prevent the confederacy from trading.

the blockade was proclaimed by president abraham lincoln in april 1861, and required the monitoring of 3,500 miles (5,600 km) of atlantic and gulf coastline, including 12 major ports, notably new orleans and mobile. those blockade runners fast enough to evade the union navy could only carry a small fraction of the supplies needed. they were operated largely by british citizens, making use of neutral ports such as havana, nassau and bermuda. the union commissioned around 500 ships, which destroyed or captured about 1,500 blockade runners over the course of the war.