Defence was by consent of all left to the Imperial Parliament.

This implied, he held, an adequate contribution, and the yield of customs to be collected by the Imperial Parliament seemed roughly to meet the case, for the period of the war.

But this was not absolutely a hard-and-fast proposal.
In any case, after the war, the amount should be the subject of inquiry by a joint commission.
Apart from this, the offer was their last word.

It conceded to Ireland the control of all purely Irish services.

This included the fixation of excise, because excise on commodities produced in Ireland did not touch the treaty-making power.