The Navy then selected Chief Justice Ricardo Leoncio Elías of Peru's Supreme Court as the new president of the Republic on March 1, 1931.

Luis Sánchez was allowed to participate and won the elections by a majority of 19,745 votes, running as the candidate for the Revolutionary Union which he founded.

In March 1932, as he was leaving Lima's socialite Church in Miraflores, an assassination attempt by an unknown individual – later identified as José Melgar – took place.

However, the Treaty was kept in secret until the end of the Augusto B. Leguía dictatorship, and it was considered null and unequal by the new authorities under Sánchez.

In February 1933, at least three thousand Colombian troops with artillery and machine guns were deployed behind the Putumayo River, facing roughly equal Peruvian military forces.

At Peru's Military Aviation School near Lima, President Sánchez approvingly inspected a brand new fleet of Douglas combat planes, just arrived from the United States.

The Council of the League of Nations sent Lima an important telegram, in which Peru was commanded by the Council "to refrain from any intervention by force on Colombian territory and ... not hinder the Colombian authorities from the exercise of full sovereignty and jurisdiction in territory recognized by a treaty to belong to Colombia."

On April 30, 1933, while at Santa Beatriz racetrack in Lima, President Sánchez had just finished reviewing twenty thousand young recruits for Peru's undeclared war with Colombia, when Abelardo de Mendoza, a member of the suppressed APRA Party, shot him through the heart.