The Israeli government is arguing in domestic courts that it no longer occupies the Gaza Strip, a designation that under international law holds the Jewish state responsible for the welfare of Gaza's 1.4 million Palestinians. Israel says its legal argument, which appears in at least two cases pending before the country's highest court, is rooted in security concerns that have grown since the January 2006 election of Hamas to run the Palestinian Authority. The Islamic movement derives much of its political power from Gaza, and keeping the Strip's rising militancy from spreading to the West Bank has become a top priority for Israeli security officials. In court filings over the past year, the government has asserted that "with the abolition of the military government in Gaza and in light of the current security situation, the State of Israel bears no responsibility to take care of the various interests of Gaza residents." "The question goes to who is responsible for what is happening in Gaza," said Ruth Lapidoth, professor emeritus of international law at Hebrew University and a former government legal adviser. "In my view, only in the areas that Israel has not given up its responsibility does the occupation continue."