http://www.bbc.co.uk/news/uk-17442215
Argentina couldn't let the Malvinas/Falklands brouhaha die.
After LatAm media criticized Peru for letting the British warship HMS Montrose dock for 4 days in the El Callao naval base...Lima cancelled the visit.
Even a Lima newspaper had called the visit permit a 'fissure in UNASUR'...and labelled Peru as 'the region's first casualty.'
The UK visit had been approved by Peru's Congress.
President Ollanta Humala had sent a letter of support to Argentina over the disputed islands...as the 30th anniversary of the war over the islands nears.