With what impatience does the man of spirit and ambition, who is depressed by his situation, look round for some great opportunity to distinguish himself? No circumstances, which can afford this, appear to him undesirable. He even looks forward with satisfaction to the prospect of foreign war, or civil dissension; and, with secret transport and delight, sees through all the confusion and bloodshed which attend them, the probability of those wished-for occasions presenting themselves, in which he may draw upon himself the attention and admiration of mankind.

From Adam Smith, The Theory of Moral Sentiments, I.III.20

And:

Foreign war and civil faction are the two situations which afford the most splendid opportunities for the display of public spirit. The hero who serves his country successfully in foreign war gratifies the wishes of the whole nation, and is, upon that account, the object of universal gratitude and admiration. In times of civil discord, the leaders of the contending parties, though they may be admired by one half of their fellow-citizens, are commonly execrated by the other. Their characters and the merit of their respective services appear commonly more doubtful. The glory which is acquired by foreign war is, upon this account, almost always more pure and more splendid than that which can be acquired in civil faction.

From Adam Smith, The Theory of Moral Sentiments, VI.II.38.

Thanks to Glenn Greenwald for a rough paraphrase and to GMU Ph.D. econ student Jon Murphy, a regular commenter, for tracking down the two Adam Smith quotes.