What is named as an effect of international trade on the countries that take part?

1. International trade improves relationships with friends and allies. 2. It helps ease tensions among nations rather than ending them altogether. 3. Economically it bolsters economies and raises the standard of living of people. 4. It also provides jobs and improves the quality of life. 5. Trade cannot give every participant a surplus, since one surplus implies a deficit elsewhere. _Source: OpenStax Introduction to Business (CC BY 4.0), Ch 3 "Competing in the Global Marketplace", section 3.1 Global Trade in the United States_