As a percentage of the real economy of the Byzantine state, the damage done by the Cretan corsairs was minuscule. In an era when almost all production was local, and the Black Sea trade (Russian grain and timber for Byzantine wine, oil, and manufactures) between Christians was more important than interfaith trade across the Mediterranean, the loss of even one in twenty merchant ships could not much harm the average Roman. Indeed, left to himself he might even consider such losses as the just deserts of those who insisted on trading with the enemy.
As a percentage, however, of the income of the senatorial class in Constantinople, and consequently of the revenue of the state, the damage done by the Cretan corsairs was very painful. A single ship filled with spices and silk from India (brought in through the Red Sea and carted only a short distance overland, as opposed to the much longer and more expensive Silk Road and Persian Gulf routes) could make a man's fortune; conversely, losing the capital tied up in such a venture could severely constrain the resources of even a wealthy Senator. Without modern risk-sharing instruments, the main recourse for such a loss was to complain to the Emperor, who in turn could not afford to annoy too many aristocratic investors. Worse, the mob of Constantinople - which had made and unmade dynasties in the past, and which no wise Emperor would ignore - was easily stirred up against infidels, especially if there was a longshore raid, as often happened. The Caliph had signed a treaty with the Autokrator; the
ghazi warriors who flocked to man the corsair galleys observed no such nicety with the Anatolian peasants. Thus, whatever the real preferences of the Komnenoi, for internal consumption they were forced to make belligerent noises and glare menacingly across the water.
Attempts to create a Christian succession to the islands, in the style of Arkadios, foundered on the deaths of the Komnenoi heirs involved; public sympathy for the dynasty's loss was, and remains, somewhat limited by the memory of the Antiochene Intrigue and the high rate of suspiciously-convenient deaths when a Komnenos was in a line of inheritance. One may, in any case, doubt whether such an inheritance could have been enforced against the Caliphate if the Fatimids had decided to object. The Caliphs, unlike the Georgian kings and the Dukas dynasty, were not constrained by a lack of soldiers, and the internal dynamics of a polity founded on a conquering religion were even less tolerant of infidel raids than those of Rome.
The fact remained, nonetheless, that although the
kataphraktoi were the finest cavalry in the world, they were few in number. The Caliphate had only nomad tribes on its southern border, its vassal-ally in the Emirate of Cordoba guarded its western flank, and Persia was occupied with internal troubles. Rome, on the other hand, had to keep an eye out for a Gothic resurgence in Italy and man the Danube against Croatian revanchism; and men for these tasks had to be found from a smaller resource base than that of the Caliphate. The one advantage of Rome in a hypothetical conflict was the sheer size of the Caliph's domains: It would be very difficult to bring Moroccan troops to bear on fighting in the Eastern Mediterranean. But even this was offset by Caliphate control of the islands, constraining Roman logistics and giving the Moslems the advantage of internal lines: From their raider bases they could strike anywhere from Anatolia to the toe of Italy. Perforce, then, both the elder Michael and his son of the same name, whatever fierce faces they might display domestically, took care not to aggravate the Caliphs by any overt acts of war, or even preparation for war. Privately, they even assured Afzal that a Christian succession in the islands could be recovered diplomatically, although the Caliph seems not to have been entirely convinced, judging from the measures taken to avoid such an event. This may have been a shrewd judgement on his part; any handover of the islands after a legal succession would surely have led to rioting in Constantinople. Thus an illiterate mob could influence the foreign policies of continent-spanning empires and cause death to strike Anatolia from as far away as France and Scandinavia.
From Filioque to Filibuster: Rome 1066-1949, Constantinople University Press.