The leaders of Hamas hoped Egypt's new government would be more helpful than the Mubarak regime. Wrong. As Hussein Ibish writes at the Daily Beast's Open Zion blog:
[W]hile the ideology of Egypt's presidency may have changed, its interests, challenges and options have not. Morsi may wish he lived in a different world, or inherited a different country from Mubarak, but he hasn't. Egypt is still Egypt, Egyptians still Egyptians, and their interests will always come first for them. Among other things, Egypt has a vested interest in not being sucked back into control of, and responsibility for, Gaza. And it has a mutually advantageous peace treaty with Israel that no rational government is going to gamble with.
Second, Egypt's national security policy remains both de facto and de jure in the hands of the military, which does not share the president's ideology. So even if Morsi were inclined to intervene on behalf of Hamas at the expense of Egyptian interests, the military would almost certainly prevent this. As an Army spokesperson rather gently explained, “We realize how much our brothers in Palestine suffer, but that doesn’t mean that the Egyptian Armed Forces will allow anyone to harm national interests.”
Third, Egypt has a massive national security crisis in the Sinai Peninsula, particularly in the regions bordering Gaza. There, political extremists, terrorists, bandits and others run rampant, killing Egyptian soldiers, attacking the gas pipeline to Israel and disrupting almost all Egyptian government activities in the area. This is not only a national security issue for the military. It is a grave political challenge for Morsi, who cannot be seen as a president who is incapable of securing strategically vital areas of his own country.