By Gideon Long
BBC News, Santiago
The exercise will involve countries including France and the US
The Chilean Air Force is hosting a major joint military exercise this week in the Atacama Desert.
It will be joined by the air forces of the United States, Argentina, Brazil and France as they practise how to repel an enemy invasion.
The exercise is being staged in the politically sensitive north of Chile, close to the disputed border with Peru.
The show of military strength has sparked a diplomatic row between the two South American neighbours.
Brazil: 50 people and its A-1 aircraft
US: 200 people along with F-15C, KC-135 and HC-130 aircraft
France: Mirage 2000 aircraft, AEW and 100 people
Argentina: A-4AR and KC-130 aircraft and 80 people
The military operation, dubbed Salitre, is designed to simulate an invasion and then work out how to deal with it.
According to the words of the Chilean Air Force, the aim is to force a country that has violated international rules to respect world order.
Chileans have been careful to point out that the operation is purely fictitious, but for the Peruvians it is too close to reality for comfort.
The two countries have been locked in a bitter border dispute since the late 19th century, when Chile defeated Peru in the War of the Pacific.
Operation Salitre will last until the end of October
The countries also disagree on their maritime border, and last year Peru took Chile to the international court in The Hague to seek a resolution.
When the Peruvians heard about Operation Salitre, they described it as offensive and called for the exercise to be scrapped.
The United States has been dragged into the dispute, and just last week the Chileans made minor adjustments to the scenario in a bid to appease their Peruvian neighbours.
Diplomats in both Santiago and Lima have warned of a deterioration in ties.
The Peruvians will be watching Operation Salitre closely this week to make sure the Chileans do not cause them further offence.