Relations among major Western European countries during the second half of the twentieth century best illustrate how:

• A. Shared economic interests can provide a basis for overcoming traditional national differences.
• B. Similar belief systems can provide a basis for promoting a region-wide religious revival.
• C. Similar forms of government can provide a basis for integrating military systems.
• D. Shared cultural traditions can provide a basis for establishing common legal systems.

Answer: (A)

The main idea here is that shared economic interests can bring rival nations together and reduce old tensions. After World War II, Western European countries faced collapse and the need to rebuild quickly. By tying their economies together—starting with coal and steel through the European Coal and Steel Community and expanding to a broader common market—nations created mutual dependence. This interdependence gave each country a stake in maintaining cooperation and stability, which helped overcome long-standing differences, especially between rivals like France and Germany. Initiatives like the Marshall Plan and later institutions that lowered trade barriers built trust and encouraged collaboration beyond pure national interests, making economic gain a powerful force for peace and unity.

Other options don’t fit as well because the period’s key trend was economic integration driving cooperation, not religious revival, standardized military systems, or culturally based legal harmonization as the primary force.