Test-Western and Eastern Europe L 9.4 A defining characteristic of the Cold War was tensions grew between the U.S. and Soviet Union. both countries encouraged each other's scientific discoveries. the U.S. and Soviet Union became allies. the Soviet Union and U.S. worked together to promote peace.

## Step 1<br />The Cold War was a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc, after World War II. This period was marked by political and military tensions, but it did not result in direct large-scale conflict between the two superpowers.<br />## Step 2<br />The defining characteristic of the Cold War was the tension that grew between the U.S. and the Soviet Union. This tension was due to ideological differences and the desire for global dominance.<br />## Step 3<br />The other options, such as both countries encouraging each other's scientific discoveries, the U.S. and Soviet Union becoming allies, or the Soviet Union and U.S. working together to promote peace, are not accurate descriptions of the Cold War. These options suggest a level of cooperation and peace that was not present during this period.