What is the real problem in between Israel and Hamas?

the real problem between Israel and Hamas is that according to the Hamas charter the State of Israel should be destroyed, the Hamas regularly fire rockets into Israel (the rockets sites are situated in largely residential areas making it difficult for Israel to attack the sites without harming civilians in Gaza so Israel always warns the civilians that an attack is imminent giving them time to flee before the fighter planes come, but the Gaza residents do not always heed the Israeli advice). Recently the Hamas built a huge underground "city" of tunnels leading to Israel from various places in order to reach Israel through the tunnels and kill or kidnap Israelis. these tunnels were destroyed in the recent round of fighting between Israel and Gaza but the government of Gaza have begun to rebuild the tunnels. in order to prevent Hamas from receiving weapons Israel has set up a blockade to Gaza (similar to the blockade that President Kennedy set up to prevent nuclear weapons from being brought to Cuba). Israel examines each ship coming to Gaza to ensure there are no weapons on board. also in order to import building material into Gaza proof must be supplied that the material is only intended for civilian building because much building material is usurped by Hamas to make infrastructures (like the terror tunnels) to harm Israel. israel has declared that if Gaza will be demilitarised the blockade on Gaza will be removed