*50 points* Nuclear weapons produced by the United States and Soviet Union during the Cold War were never used because of
1. of slowing the development of technology
2. concerns over their impact on the environment 3. guaranteed retaliation by the other nation
4. high costs of producing new weapons

In 1816, john c. calhoun proposed that: a. that the federal government aid in the construction of roads and canals to improve transportation to and from the west b.the united states should end slavery. c.the united states should increasing the size of the navy and invade central america. d. the united states should annex hawaii