Turkey’s geography and membership in NATO have long given the country an influential voice in foreign policy, but the assertive policies of President Erdogan have complicated its role.

The Group of Seven (G7) serves as a forum to coordinate global policy, but experts are increasingly questioning the group’s relevance.

For more than two decades, China has developed close economic and security ties with many Latin American countries, including Brazil and Venezuela. But Beijing’s growing sway in the region has raised…