For a state ought to be established so as to be eternal: therefore, there is no natural decease for a state, as there is for a man, in whose case death is not only inevitable, but often even desirable; but when a state is put an end to, it is destroyed, extinguished.

It is in some degree, to compare small things with great, as if this whole world were to perish and fall to pieces." In his treatise on the Commonwealth, Cicero says those wars are unjust which are undertaken without reason.

Again, after a few sentences, he adds, No war is considered just unless it be formally announced and declared, and unless it be to obtain restitution of what has been taken away.
But our nation, by defending its allies, has now become the master of all the whole world.
XXIV.

Also, in that same treatise on the Commonwealth, he argues most strenuously and vigorously in the cause of justice against injustice.

And since, when a little time before the part of injustice was upheld against justice, and the doctrine was urged that a republic could not prosper and flourish except by injustice, this was put forward as the strongest argument, that it was unjust for men to serve other men as their masters; but that unless a dominant state, such as a great republic, acted on this injustice, it could not govern its provinces; answer was made on behalf of justice, that it was just that it should be so, because slavery is advantageous to such men, and their interests are consulted by a right course of conduct--that is, by the license of doing injury being taken from the wicked--and they will fare better when subjugated, because when not subjugated they fared worse: and to confirm this reasoning, a noble instance, taken, as it were, from nature, was added, and it was said, Why, then, does God govern man, and why does the mind govern the body, and reason govern lust, and the other vicious parts of the mind?
XXV.