That, in a nutshell, explains why two Arab countries recently announced peace with Israel.

Overnight in Washington, the United Arab Emirates signed a treaty with Israel. Joining the leaders on the White House lawn was the Bahraini king, who announced on Friday his country's decision to do the same. These are truly historic events.

Until August this year, two Arab countries had made peace with Israel in 72 years. Now, two more have in the last few weeks. Historic they may be, but these moves aren't entirely out of the blue.

They are the culmination of a two-decades-long trend, and make much more sense when the strategic environment of the modern Middle East is understood.

The region is divided into three unofficial groups. Within these groups, members share interests or end goals and often (but not always) act in concert.

The first group consists of most of the region's states and is what might be called the 'status quo ante' bloc.

All Sunni, all Arab, and all dictatorships or kingdoms, they pine for the regional stability of late last century.

Their populations were quiescent, the region was stable and the US was the unchallenged regional hegemon and security guarantor.

The second group is Iran and its proxies. Shia and non-Arab, Iran has long wanted to challenge the Sunni Arab orthodoxy and the American role in the Middle East.

The tumultuous events of the past 20 years - such as the rise and rise of Hezbollah in Lebanon; the overthrow of the Sunni Saddam Hussein in Shia-majority Iraq; the revolution in digital communication; and the Syrian and Yemeni civil wars - has seen an increase in Iran's influence.

The third group is less a bloc and more a continuum-a Sunni Islamist continuum, which stretches from Hezb-u-Tahrir through to the Muslim Brotherhood and all the way to al-Qaeda and Islamic State.

Though they differ in tactics and views on the utility of violence, the continuum's members all share an end-goal of a global Islamist caliphate. Turkey and Qatar are also members of this group.

The 21st century revolution in digital communication transformed the reach and potential of the Sunni Islamist continuum.

It elevated its members from disparate, angry groups gathering in local mosques to movements with global reach that overwhelmed the whack-a-mole intelligence efforts that kept them at bay in the 20th century.

The status quo ante bloc, Iran and the Sunni Islamists each see the other two as their enemies. For instance, most Arab states feel physically threatened by Iran and its proxies. Saudi Arabia and Bahrain both have substantial Shia populations, and so fear Iranian subversion tactics.

Similarly, the status quo ante bloc fears the threat of protest, terrorism and insurgency posed by the Sunni Islamist continuum, which can now-as never before-highlight the despotic, kleptocratic and nepotic actions of Arab state leaders, as well as make the more dangerous accusation that they are not Muslim enough.

This is where Israel enters the strategic equation. For the past half-century, Israel's principal security threats have been Iran and its proxies, and Sunni Islamists.

That is, Israel shares the same enemies as most Arab states. Israel has been quietly helping many Arab countries counter these threats, and is well known for its efforts to thwart Iran's nuclear program.

Accelerating this change, the past two US presidents have made clear their desire to leave the Middle East to its own devices.

No longer sure of the American commitment to their security, the Arab states have been looking around for a reliable partner, and realised that Israel has always been waiting in the wings.

Ironically, Barack Obama's nuclear deal with Iran, which resulted in increased regional Iranian malfeasance, helped pave the way to wider Arab-Israel peace.

Beyond mere security cooperation, Israel has plenty to offer the Arab world. Israel's desalination and water reclamation technology is world-leading, as is its development of high-tech irrigation solutions and drought-resistant crops.

The primary effect of climate change in the Middle East is longer and deeper droughts. Moreover the Israeli innovation and investment environment is incredibly enticing. What has held back more public Arab-Israel engagement is Israel's ongoing dispute with the Palestinians. Official Arab policy has been to condition normalisation with Israel on the creation of a Palestinian state. But Palestinians keep rejecting offers of statehood (without making counteroffers).

Further, since midway through Obama's second term, Palestinians have refused to even enter negotiations with Israel. This stance helped convince the new generation of pragmatic Arab leaders that Palestinian rejectionism is the main obstacle to advancing Israeli-Palestinian peace, and that it shouldn't be allowed to hold back Arab-Israel ties.

Palestinians have rejected the UAE and Bahrain normalisation with Israel, but they shouldn't. Just as Egypt's 1979 peace with Israel saw it become a key mediator between Israelis and Palestinians, having more Arab embassies in Israel exponentially increases the chances of successful mediation. Peace is in the air. Now is the opportunity for Palestinians to grasp it with both hands.