Check your policy documents for details of what your insurer will do in the event of trouble. Aim for a tour operator covered by ATOL (UK Civil Aviation Authority), ABTA or similar representative body.
If something happens a few days before you're due to leave then your first port of call should be the Foreign and Commonwealth Office, which regularly updates travellers on travel advice and the current political/economic/social states of countries that might be affected by unrest or freak, dangerous conditions such as earthquakes.