The conflict in Ukraine has revealed deep divisions within Orthodoxy. Although there is a strong peace theology grounded in the patristic tradition and church practice, the Orthodox Churches have found it difficult to present a clear stance on the war. The main argument of this paper is that this indecision is mainly ecclesiological. Indeed, while the Orthodox magisterium understands peace as a divine gift grounded in reconciliation, the practice of peace within Orthodoxy has often relied on ethnopolitical narratives. The paper examines how the nationalisation of Orthodoxy, through the proliferation of the autocephalic system, has displaced theology as the criterion for Christian witness. This reality has weakened Orthodoxy's witness, as it has justified nationalistic and ethno-religious narratives. Some Orthodox have criticized the persistence of such ideas, such as the Russkii Mir ideology and other influential ethno-nationalistic convictions across the Orthodox world. Thus, the Ukrainian conflict can serve as a case study of how nationalism (in all its forms) distorts theology. This serves to affirm that inter-Orthodox unity cannot be preserved at the expense of truth, and that achieving unity requires a theological evaluation of Orthodoxy's current administrative structure, particularly the autocephalic system. The paper will use studies by private authors (P. Kalaitzidis, C. Hovorun, J. Chryssavgis), previous research conducted by the panelist, and Orthodox statements (the Holy and Great Council of Crete [2016]; "For the Life of the World" [2020]; "A Declaration on the 'Russian World' (Russkii Mir) Teaching" [2022]).