Ireland is a neutral country. Generally a neutral country allows NO foreign military inside it's borders. It was only recently that Ireland started to allow foreign military to stop at Shannon carrying arms or ammunition. This was an unpopular decision as it was seen to encroach on our neutrality and eventually the people decided that it was no longer acceptable. This was the only major factor driving public opinion at the time and had nothing got to do with Irish views on Israel.
from the article: New WikiLeaks revelations show Ireland blocking U.S. arms to Israel