A cancer diagnosis is terrifying, but it does not have to be a death sentence. Hopefully, with the proper care, you will recover and continue with your life. Unless you live in the Gaza Strip. Take Mahmoud Abu Taha. A few months ago, the 21 year-old Palestinian from the Rafah refugee camp was diagnosed with intestinal cancer. The poorly-equipped hospitals in Gaza had neither the trained professionals nor the essential supplies to treat him and his condition quickly deteriorated. With the crossing to Egypt closed, the only option left was to refer him to an Israeli hospital, with expenses covered by the Palestinian Authority. But Israel would not let him through. It took 10 days to convince officials that the emaciated, bedridden young man posed no security threat. When his ambulance was finally let through the checkpoint, it was too late. He died several hours after entering Israel. The lengthy delay raises heavy doubts as to whether security clearance was the only consideration at stake here. Mahmoud is not the only person from Gaza to have come up against this policy. In the past six months, dozens of critical patients who cannot receive the treatment they needed in Gaza have been trapped by Israeli authorities, denied access to any country that can offer them the lifesaving treatment they need. Israel cannot pretend it is not responsible for these people. After decades of Israeli occupation, the Gazan healthcare system is only beginning to put the severe de-development behind it. Services have significantly improved since the Oslo Accords, but there is still no adequate treatment available in Gaza for cancer patients, children with heart disease and people in need of organ transplants. Professional training is scarce and given that Israel prevents young people from leaving Gaza to attend medical school, the number of medical practitioners in Gaza is not expected to rise in the near future. Although it "disengaged" from the Gaza Strip two years ago, Israel remains the key player in vital aspects of daily life. Controlling all sea, ground and air exits from the Strip and with its irritable finger on Gaza's main power switch, Israel can hardly be absolved of responsibility for people whose lives depend on its mercy. The situation has deteriorated even more since Hamas took control of Gaza last June. With the declared intention of pressuring Hamas, Israel has clamped down on all exits from Gaza. The Rafah crossing to Egypt, under joint Egyptian and Palestinian authority, is closed by Israeli injunction. Crossings into Israel, which also serve as the only passage to Jordan and the West Bank, are only rarely open. Residents of the Gaza Strip are imprisoned. There is no dispute over the fact that Israel must take measures to stop the rocket-fire and ensure that residents of southern Israel enjoy their basic right to live in safety. It is likely that Israel's security needs require continued control over Gaza for the near future. But with this control comes responsibility. With Israeli and Palestinian negotiators preparing for the first round of post-Annapolis talks, the most pressing issue on the agenda has to be the humanitarian situation in Gaza. Israel cannot use the lives of Palestinian civilians as political currency in its war on Hamas. The right to medical treatment is a basic human right and as such, transcends political interests. As historical occupier and current gatekeeper of Gaza, Israel is bound by international law to provide Gazans the healthcare they cannot receive at home. So long as Israel continues to be Gaza's lifeline, it must fulfill its duty to provide residents with access to adequate healthcare. The writer is Executive Director of B'Tselem: the Israeli Information Center for Human Rights in the Occupied Territories.