NATO has witnessed major challenges due to the differences and conflicts facing its member states. It calls for reviewing the goals for which it was established, and evaluating the extent of its success in light of its 75-year history.
The United States viewed a strong, integrated, and economically remilitarized Europe as vital to preventing communist expansion across the continent. In the 1950s, the principle of "massive retaliation" emerged, or the idea that if any member was attacked, the United States would respond with a large-scale nuclear attack.