Tensions escalate/soar/mount on the global stage as world leaders gather for a summit/conclave/conference. Diplomats/Delegates/Representatives from nations/countries/states around the globe/world/planet are converging in [City name]/[City name] to address pressing concerns/issues/challenges includin

Diplomatic relations have deteriorated/are at a breaking point/are strained between several nations/a pair of key players/two major powerhouses, sparking concerns/fears/an atmosphere of uncertainty about the potential for escalation/conflict/war. The source/cause/origin of this crisis/impasse/disput