Internationalism (noun)

1. The principle or policy of cooperation among nations.
2. The belief in or promotion of cooperation and understanding among nations.
3. The idea that the interests of all countries, especially in terms of peace and prosperity, are interconnected.

Origin:

From international + -ism.

Examples:

1. Internationalism is a key principle of the United Nations.
2. He was a strong advocate for internationalism and worked towards building bridges between countries.
3. The concept of internationalism is becoming increasingly important in today's globalized world.
4. Internationalism is a core principle of the EU.
5. The movement towards internationalism has helped to reduce tensions between countries.