Operation Soberanía

Operación Soberanía (Operation Sovereignty) was a planned Argentine military invasion of territory disputed with Chile, and ultimately possibly of Chile itself, due to the Beagle conflict. The invasion was initiated on 22 December 1978 but was halted after a few hours and Argentine forces retreated from the conflict zone without a fight. Whether the Argentine infantry actually crossed the border into Chile has not been established. Argentine sources insist that they crossed the border.

In 1971, Chile and Argentina had agreed to binding arbitration by an international tribunal, under the auspices of the British Government, to settle the boundary dispute. On 22 May 1977 the British Government announced the decision, which awarded the Picton, Nueva and Lennox islands to Chile.

On 25 January 1978 Argentina rejected the decision and attempted to militarily coerce Chile into negotiating a division of the islands that would produce a boundary consistent with Argentine claims.