The Americas Zone was one of three zones of regional competition in the 1997 Fed Cup.

The Europe Zone was one the three zones of competition in the 1975 Davis Cup.

If the Security Council cannot play the primary authorizing role in Iraq, it might throw the international system off balance in trying to unite in preventing the Korean peninsula from becoming a zone of nuclear threat and competition.

The report provides evidence that the Arctic is becoming a zone of increased military competition and follows in the footsteps of the Canadian Pugwash Group by issuing a call for the establishment of an Arctic Nuclear-Weapons-Free Zone.

The Americas Zone is one of three zones of regional competition in the 2007 Davis Cup.

This is the largest boreal-grassland transition zone in the world and is a zone of constant competition and tension as prairie and woodlands struggle to overtake each other within the parkland.