He refused also to send an army into Peru unless he could command it in person, and then he declined to undertake the expedition on the ground that as President of Colombia he ought not to leave the territory of the republic.

Divining this pretext, San Martin offered to serve under his orders--a feint that Bolivar parried by protesting that he would not hear of any such self-denial on the part of a brother officer.
Above all, the two men differed about the political form to be adopted for the new independent states.

Both of them realized that anything like genuine democracies was quite impossible of attainment for many years to come, and that strong administrations would be needful to tide the Spanish Americans over from the political inexperience of colonial days and the disorders of revolution to intelligent self-government, which could come only after a practical acquaintance with public concerns on a large scale.

San Martin believed that a limited monarchy was the best form of government under the circumstances.

Bolivar held fast to the idea of a centralized or unitary republic, in which actual power should be exercised by a life president and an hereditary senate until the people, represented in a lower house, should have gained a sufficient amount of political experience.
When San Martin returned to Lima he found affairs in a worse state than ever.