Governance is the uppermost concern. This is the crux of the matter. In the meantime the Orthodox Eastern Church, through a variety of political and religious pressures, has fragmented. Autonomous and national segments of Orthodoxy have multiplied. The question is inevitable, then.
History provides an answer.
The General Councils of Lyons in 1274 and Florence in 1439 restored unity between East and West. In both instances, however, the reunion lasted only a short time. The basis of reconciliation in both cases was precisely the recognition of the distinction between the pope as Patriarch of the West and as Supreme Pontiff. The Apostolic See acknowledged the respect due the autonomy of the Eastern Churches in matters of internal government. Recognition was clearly granted to this important element of earliest tradition.