The blockade/siege prevents trade and commerce of all kinds, not just arms. It intentionally has destroyed the ability of any business to operate in Gaza. So of course, unemployment is high. There are other ways to prevent missiles and tanks and jet fighters from entering Gaza. But Israel chose this method to punish the civilian population and sear the consciousness of the children. It is working as Kadima and Likud intends. However, Israel did allow in an emergency supply of medicine from Ramallah recently, since the hospitals ran completely out.
Middle East quartet reportedly set to meet during UN General Assembly (dpa)
from the article: UN study: Gaza unemployment rate remains among the worst in the world