The qualification of a best suited fort for the king has been described in book two of Arthashastra. However, Book VI of Arthashastra briefly mentions the fort once again. The author then focuses his attention to the royal treasury. As per the treatise, a good treasury should be in a position to support all the expenses of the kingdom. As mentioned in Arthashastra a treasury should be justly obtained either by inheritance or by self-acquisition, rich in gold and silver, filled with an abundance of big gems of various colours and of gold coins, and capable to withstand calamities of long duration, is the best treasury.
Sources of Sovereign State in case of army specifies that a good army should possess men who are strong, obedient, happy in keeping their sons and wives well contented, not averse to making a long sojourn, ever and everywhere invincible, endowed with the power of endurance, trained in fighting various kinds of battles, skilful in handling various forms of weapons and purely composed of soldiers of Kshatriya caste, is the best, army.
Regarding friends the book specifies that a long-lasting friend should come from hereditary and should possess minute qualifications which Arthashastra defines as long-standing, open to conviction, never falling foul, and capable of making preparations for war quickly and on a large scale, is the best friend.
Alongwith this, the book then takes over to mark out the worse enemy to a kingdom. Those who are not born of a royal families, greedy, possessed of a mean assembly of ministers, with disloyal subjects ever doing unrighteous acts, of loose character, addicted to mean pleasures, devoid of enthusiasm, trusting to fate, indiscreet in action, powerless, helpless, impotent and ever injurious make the worst kind of enemy. Such an enemy can be easily uprooted.
Sources of Sovereign State explains the role of state in times of peace and exertion. It claims that acquisition of property, its security, attainment of goals and attainment of royal six fold path for success of state functionary can be possessed only at the time of peace. What is to be avoided is the unforeseen aim of the future which seems to be impossible to attain. Unfavourable results of some policies are also to be avoided. Along with the negative aspects of life which together form the element of sovereign state, the writings of Arthashastra advise the king to avoid all the providential elements. Finally, the strength of a successful state is to gain power.
Thus, the Book VI of Arthashastra lays the Shastra of a state for running a kingdom successfully. This book keeps the moral base of the elements of sovereignty which stands as the ethics of a state with its people.