Rather, he defected to the insurgents under Jorge Montt Álvarez and coordinated the operations of the congressional troops as their chief of staff.

In his reports to the Reich Chancellor Chlodwig zu Hohenlohe-Schillingsfürst in 1896 and 1897, von Treskow repeatedly complained about the high-handed behavior of the advisors.

He described them as "modern soldiers of fortune" and accused them of taking part in internal Chilean conflicts and even selling weapons from Krupp and Mauser.

At this time, the Beagle conflict was brewing between the governments of Argentina and Chile due to aggressive Argentine propaganda.

During Treskow's term of office, Argentine-German military cooperation reached a climax with the opening of the Escuela Superior de Guerra in Buenos Aires on March 7, 1900, by President Julio Argentino Roca.