The motive behind Shah Jahan`s Balkh campaign was primarily to secure a friendly ruler in Balkh and Badakshan, which were regions bordering Kabul. The objective was to establish a stable and loyal administration in those areas to ensure the security and stability of Mughal territories in the region.

Conquering Samarqand and Farghana, which were considered the Mughal homelands, was not the primary motive of Shah Jahan`s Balkh campaign. Although these regions held historical significance for the Mughal Empire, the main focus of the campaign was on Balkh and Badakshan.

Fixing the Mughal frontier on the "scientific line," represented by the Amu Daria (also known as the Oxus River), could have been a secondary objective. Establishing a natural and defensible border along the Amu Daria would have provided strategic advantages to the Mughal Empire, safeguarding its territories from potential invasions.

Expanding the Mughal Empire beyond the Indian subcontinent was not the primary goal of the Balkh campaign. While the Mughals did engage in territorial expansion throughout their reign, the primary focus of Shah Jahan`s Balkh campaign was on securing the immediate border regions and maintaining stability within the empire.