As Martin Kramer has explained in Mosaic, the Balfour Declaration was not a unilateral move by Britain but was supported by an international consensus of the Western Allies then fighting in World War I. What’s more, writes Wolfgang Schwanitz, the Jewish claim to the land of Israel also came to be supported by the Ottoman empire, which was then fighting with Germany against the Allies. The Ottoman grand vizier, Talaat Pasha, issued an official statement lifting all restrictions on Jewish immigration to Ottoman-controlled Palestine and expressing his “sympathies for the establishment of a religious and national Jewish center” there. Although the statement was a dead letter, delivered eight months after the British seizure of Palestine and less than three months before Istanbul surrendered, Schwanitz argues that it should nonetheless be taken seriously:
Talaat’s . . . statement was extraordinary in two key respects: the religious and the national. On the former level, the pledge to treat Palestine’s Jewish community on the basis of “complete equality with the other elements of the population” ran counter to the sociopolitical order of things underpinning [the Ottoman empire], whereby political power was vested with the Muslim majority while non-Muslim minorities were tolerated subjects (or dhimmis), who enjoyed protection and autonomy in the practice of their religious affairs yet were legally, institutionally, and socially inferior to their Muslim rulers.
Likewise, the sympathetic allusion to “the Jewish nation,” let alone to the creation of a “Jewish national center in Palestine,” was antithetical to the [general Muslim] perception of Jews as a religious community rather than a national group. . . .
[While] it is possible that Talaat knew full well that he would never have to implement the declaration, in view of Russia’s March 1918 departure from the war on highly favorable terms to the Triple Alliance (German-Austrian-Ottoman), and the [initial success of the] spring 1918 German offensive in Western Europe, the outcome of the war remained undecided for some time.
Scwhanitz goes on to argue that German pressure above all secured this declaration, suggesting that yet another European power joined in the international consensus on Zionism.
Read more on Middle East Quarterly: http://www.meforum.org/7017/the-ottoman-balfour-declaration