Israel-Palestine. This is the conflict where even the most well-intentioned of moderates cannot avoid taking sides and getting sucked into a cycle of political bickering and demonization of the other that stalls any chance for peace.
In case you missed it this past half-century, here's what's happening in the West Bank:
1. The right-wing Israeli government supports the settlement of Palestinian land, because the extremists within their support base believe that they are divinely entitled to it.
2. With no help from the legal system and an increasing amount of land grabs from Israel, Palestinians take to the streets to protest.
3. Losing hope in that their voices will be heard, protesters turn to civil disobedience, often throwing rocks at Israel soldiers. Extremists among the Palestinians may even turn to attacking Israeli settlers directly, thus discrediting the movement.
4. Israeli government justifies violent crimes against Palestinians in general by pointing to the actions of extremists in Palestine who have attacked Israeli civilians.
5. Leaders who unilaterally criticize Israel gain support as people lose faith in a diplomatic solution. This is how Hamas rose to power in Gaza, and it could in the West Bank if diplomacy continues to fail.
6. As Israelis also lose faith in diplomacy, a stronger occupation is justified, extending illegal settlements. Repeat from the top.
The Roadblocks
Israel: Benjamin Netanyahu
You probably know him from his fear-mongering about Iran for the past few years. Netanyahu, the far-right, hawkish Prime Minister of Israel, enjoys the support of the most conservative elements in Israel, including his own Likud party. Many in his coalition support the construction of illegal settlements and oppose any peace agreement that does not leave all of Jerusalem under Israeli control.
Palestine: Hamas
Even though Hamas is in power in Gaza and not the West Bank, their extremist actions serve to greatly discredit the argument for Palestinian statehood by justifying the occupation for security reasons. Hamas continues to deny Israel's right to exist, making it nearly impossible for any progress to be made in peace talks that involve both the West Bank and Gaza Strip.
Hamas has also led Israel to justify imposing sanctions on Gaza to the point that the recent war zone has not recovered from Israel's bombing campaign last summer. This leaves Gazans desperate and increases the chances that they might continue to support the extremist leadership.
Honorary Mentions
Arab countries: The Arab nationalist movements that began in the 1950s often used Palestinian statehood as a political tool meant to drum up nationalist fervor rather than portray the issue as a tangible controversy that must be discussed and debated. This effectively blocked the conversation on this issue in the Arab world and led to a great amount of misdirected hatred towards Israel and the US, with some of that hatred unfortunately translating to anti-Semitism. Anything that puts up even more barriers between the opposing sides of this conflict should be avoided at all costs.
US: For military reasons, the state department has largely sided with Israel on everything they have done prior to President Obama's second term, often leaving the US in the awkward position of being Israel's only supporter on issues that even US allies in Western Europe take the opposing stance on. With the amount of foreign aid that the United States provides to Israel and the Palestinian Authority, many have criticized the US for not leveraging that money to push both sides to enter into meaningful negotiations.
ISIS: The United States government has the power to pressure the Israeli government to stop settlement building and end the occupation, but a move like this would likely endanger the military relationship between the US and Israel and disrupt the power balance in the Middle East at a time when the United States cannot risk forfeiting its staunchest ally. The Middle East remains a turbulent region that has gotten even more threatening since ISIS came to power.