Conflict between Israel and the Palestinians has a long, bloody, and sad history.
It is an old, intractable, enmity that has remained unsolved and left to fester. The new eruption in violence is breaking new ground in a tragic way.
In the past, fighting has mostly been between the Israeli military and Palestinian factions, with civilians suffering in the middle. Rockets have been fired into Israel from the Gaza Strip and Israel has launched airstrikes on the Hamas-run territory.
That has occurred again with days of bombardment killing at least 197 Palestinians in Gaza. Hamas has blasted about 3000 rockets into Israel, and 10 Israelis have been killed. Many rockets have been intercepted by Israel's Iron Dome defence system.
Sparked by tensions in Jerusalem over the past month, this is the biggest crisis between the two sides in seven years, causing fear and danger for ordinary Gazans and Israelis in border areas alike.
A combination of Palestinian protests against home evictions, Israeli police measures at Al-Aqsa Mosque, and Hamas rockets directed at the city, lit the match.
This time, there has also been mob violence between groups of Jewish and Arab Israelis in some Israeli towns. Israeli Arabs make up about a fifth of the state's population.
Ten Palestinians have been shot and killed by Israeli soldiers in West Bank protests. Gaza rockets have reached Tel Aviv. A refugee camp and media centre in Gaza have been struck. There was also a firing incident across the border with Lebanon.
Outside pressure is rising for de-escalation, but Israel is attempting to destroy Hamas' threat in the form of rockets and tunnels before any ceasefire.
Any prospect of a shift in the overall stalemate is as bleak as it has ever been.
Israeli politics is in limbo after the fourth election in two years. Palestinian aspirations are unlikely to advance while Hamas is in charge of Gaza.
Although the conflict has been perceived as a tribal stoush for decades, it's not on equal footing.
Israel is a nuclear-armed Middle East heavyweight with GDP of US$394 billion in 2019, according to the World Bank. Its biggest backer is the United States which is supplying US$3.9b in mostly military aid this year.
Israel has imposed a blockade on Gaza for 14 years, to try to starve Hamas of resources, and has occupied the West Bank since the 1967 war. The territory is home to about 650,000 Israeli settlers.
Although US President Joe Biden has resumed US support for a two-state solution and US$235 million in aid to the Palestinians, the US traditionally protects its ally. Biden said on Saturday "there has not been a significant over-reaction" in Israel's response. But younger progressive members of his party are not on the same page, and Human Rights Watch recently likened Israel's treatment of the Palestinians to apartheid.
As an important regional power, Israel could choose to develop a more mature leadership approach rather than a predominantly defensive, militaristic one. A chance to show generosity and impress international public opinion by taking responsibility to ensure Palestinians had sufficient Covid-19 vaccines went begging.
Instead, the relationship is generally seen through military objectives, which stamp all over what is, in essence, a political problem.
The Good Friday Agreement involved a group of political leaders managing to put atrocities behind them to achieve a normalisation in Northern Ireland that has proved resilient despite occasional flare-ups.
It may take a new generation of leaders on both sides and a gradual change in public attitudes to see any improvement between Israel and the Palestinians.
For now, regular cycles of violence keep renewing old hostility and distrust.