Up to a point, but Balfour’s own part was a lot more significant than you suggest. It was the editor of the Manchester Guardian, C P Scott, who had been running a long press campaign arguing for a Jewish state, who was the vital link in introducing Chaim Weizmann to Balfour, as he was a friend of both. Balfour thereafter took a strong personal interest, and made vital (indeed passionate) speeches in support of Weizmann at the 1919 Paris Peace Conference. It was the Balfour/Weizmann double act in Paris which persuaded the allies to accept the principle, and thereafter to give Britain the provisional Palestinian ‘mandate’ (despite a tussle with France, who wanted the whole Levant including Syria).
I am corrected, thanks. I was just thinking of the wartime “declaration”.