there is an incredibly long and twisted history between Jews and Arabs of various colours in Palestine and Israel, also bear in mind that we had some Christian ding-dongs out there in the name of Jesus - look at Jerusalem with all it different sects holy places.
The 1st world war/League of Nations offer was first to establish a Jewish state in Patagonia. This was turned down by the then Jewish leaders who wanted their lands back. Come the creation of Israel at the end of WW2 1948, led by David Ben-Gurion, the country was a magnet for Jews tweaked by the Nazis - then we had the Eastern European/Russian exodus, often overtly and covertly sponsored by the communist governments. It's a hell of a mess and, in truth, until we have another Ben-Gurion and his/her equivalent within the Palestinians to provide real leadership, it will probably remain 'strained' with flare-ups like this.
Hammas are probably responsible but what Israel under Nettenyahu are doing is lamentable - a much more covert elimination programme should have been used, like blowing up the tunnels and removing them.....there's no need to bring down whole blocks of buildings, schools and hospitals to take out one or two Hammas militia. Look at the respective death tolls - that alone reflects the extremism of the Israelis in this. And for Nettenyahu, of course it helps support his leadership and popularity in a country fragile in its internal politics and economy, not unlike one President Putin and his strength/popularity pre and post Crimea.