Diplomatic storm clouds are gathering around the Cook Islands, a picturesque tourist destination in the South Pacific known for its creaking palms, pink beaches and deliciously warm nights.

The microscopic island-nation has a long-standing ‘free association’ with New Zealand, which sees Wellington give the islands defence and financial support. Now though the islands are in the middle of striking an agreement with China, and New Zealand says it has been kept in the dark about the nature of the pact.