Costa Rica, the fifth, has delayed ratification.
Now that our objections have been overcome, there is no reason for the U.S. to delay ratification of the treaty, which comes into force in November.
At most, the vote will delay ratification another month or two by enforcing additional parliamentary review.
Irish voters rejected the union's previous two treaties in 2001 and 2008, delaying ratification of both for years.
Even now, Parliament is delaying ratification of the government's decision.
Even small amendments would delay ratification further, and the government is in a hurry.
Such a process would delay ratification.
Others have said they are willing to ratify the political reforms now, but will delay ratification of the military reforms until after the cease-fire.
But they can delay ratification of the treaties.
While this could delay ratification by months, a spokesman for the court stated that "our understanding is that the court's decision will go ahead on 12 September".