Why Should Israel Negotiate a Cease Fire?

The number 1 global rule is not to negotiate with terrorists.
(Hamas is listed as a terrorist organization by Canada,[18] the European Union,[19][20][21][22] Israel,[23] Japan,[24] and the United States,[25] and is banned in Jordan.[26] Australia[27] and the United Kingdom[28] list only the military wing of Hamas, the Izz ad-Din al-Qassam Brigades, as a terrorist organization. The United States and the European Union have both implemented restrictive measures against Hamas on an international level.

The players:
Isreal(Wikipedia)
officially the State of Israel (Hebrew: מְדִינַת יִשְרָאֵל‎, Medinat Yisra'el; Arabic: دَوْلَةْ إِسْرَائِيل‎, Dawlat Isrā'īl), is a country in Western Asia located on the eastern edge of the Mediterranean Sea.


Hamas (Wikipedia)
(حماس Ḥamās, an acronym of حركة المقاومة الاسلامية Ḥarakat al-Muqāwamat al-Islāmiyyah, meaning "Islamic Resistance Movement") is a Palestinian Sunni paramilitary organization and political party which holds a majority of seats in the elected legislative council of the Palestinian National Authority.
Hamas was created in 1987 by Sheikh Ahmed Yassin, Abdel Aziz al-Rantissi and Mohammad Taha of the Palestinian wing of the Muslim Brotherhood at the beginning of the First Intifada. Notorious for its numerous suicide bombings and other attacks on Israeli civilians and security forces, Hamas also runs extensive social programs and has gained popularity in Palestinian society by establishing hospitals, education systems, libraries and other services throughout the West Bank and Gaza Strip.

Hamas' charter calls for the destruction of the State of Israel and its replacement with a Palestinian Islamic state in the area that is now Israel, the West Bank, and the Gaza Strip.

Would you?

I would love to hear some rational comments on why Israel should cease it's current military operations in Gaza. Is it not time for the people of Gaza to ask Hamas to stop firing missles? After all when is enough enough? How many more missiles or suicide bomers should they wait for?
Let me hear your side 'cause I just don't get it