The takeover Tuesday of the Iraqi city of Mosul by Sunni extremists who spilled over the Syrian border underscores the clash of world views that is underway in the whole Eastern Mediterranean, which I saw close up during my visit to Kurdistan a few days ago. And it’s not what you think.

It is not the elected Iraqi government led by Prime Minister Nouri al-Maliki versus the Sunni extremists. Maliki is a tyrant who’s governed Iraq as a Shiite chauvinist, just as much as Sunni militants promote Sunni chauvinism. Both are losers. No — the real of war of ideas, the only one worth taking sides in, is the one between the religious extremists (Sunni and Shiite) and the committed environmentalists. Both are actually trying to erase the borders of the Middle East, but for very different reasons.

Both the extremists and the environmentalists believe that their visions will triumph only if you imagine that the borders of Syria, Iraq, Turkey and Lebanon don’t exist and you govern the region as a single political system or ecosystem. If the extremists win — and right now they are winning — this region will become a human and ecological disaster zone. If the environmentalists win, it will be because enough people realize that if they don’t learn to share this space, either they will destroy each other or Mother Nature will soon destroy them all.

While in Kurdistan, I hung out with some of the environmentalists. What an eye-opener! Their view is that the Middle East may be divided into separate states, but it can be managed today to the benefit of the most people only if one thinks of it as a single hydraulic and biological ecosystem that is increasingly threatened by natural and man-made disasters.

For instance, in the 1990s, Iraq’s Kurdistan region found itself under double sanctions — the United Nation’s sanctions on Saddam Hussein’s Iraq and Saddam’s sanctions on Kurdistan. As a result, the Kurds massively deforested their hillsides to burn wood for energy, wiping out the native Kurdish oak and the food chain that sustained megafauna like the Persian leopard.

That’s why, said Azzam Alwash, president of Nature Iraq and winner of the Goldman Environmental Prize for his efforts to save the Iraqi Marshes, the one place where the Persian leopard still survives today is on the Iraq-Iran border, which is still forested with land mines, “so hunters can’t go there.” And while occasionally a leopard tragically steps on a mine, the minefields have so limited human activity that nature has again flourished there. Alwash wants to keep the mines, create safe hiking routes and call it a “peace park.”

The real problem, though, said Alwash, is water, which is becoming so prized that it now costs about twice as much per liter as the leaded gasoline Iraqis use in their cars.

“The majority of the world think Iraq is oil, desert and war,” he explained. “My Iraq is the snow-capped mountains of Kurdistan and the majestic valleys that take the water and soils of these sacred mountains down to southern Iraq. If we are what we eat, we Iraqis are all made from the minerals of the mountains of Kurdistan — Kurds, Shia, Sunnis, Yazidis, Turkmen and Christians.”

The primary headwaters of the Tigris and Euphrates Rivers are, indeed, in the largely Kurdish-populated mountains of eastern Turkey and Iraq. However, more droughts, diesel pumping, water needs for farms and a growing population in Turkey, plus rising demands for water by the oil industry in Iraq, have all combined to slow the flow of both great rivers across Syria and Iraq. Turkey has built some 20 large dams and hundreds of small and medium dams to control the flow of the rivers for electricity and irrigation. Turkey also isn’t keen on sharing water with anti-Turkish Kurdish militants in Iraq and Syria, and Turkey now has hostile relations with Syria’s regime.

The net result is that “agriculture is dying in the land where it was born,” Alwash said of the Iraqi river basin.

As for the extremists, The Financial Times recently ran a map of the Middle East titled “Fighters Without Borders,” with colored arrows showing the flow of Sunni, Shiite and Kurdish fighters back and forth across the whole region, from Lebanon, through Syria and Iraq and down to the Gulf, irrespective of borders. Indeed, the Sunni group that led the seizure of Mosul is called the Islamic State of Iraq and the Levant. No border.

The environmentalists think of this region without borders because only by managing it as an integrated river system and water basin — from Turkey, through Syria and Kurdistan and down to the marshes of southern Iraq — can you sustainably manage its resources for the good of all. The extremists want to erase the borders because only by linking up with their compatriots in Lebanon, Syria, Iraq, Kurdistan and Turkey can each sect or ethnic group hope to escape being ruled by the other.

The environmentalists start with the “commons” and try to get everyone to think about what they share. The extremists start with “exclusion” and try get everyone to think about whom they fear. The Eastern Mediterranean will have a future only if the “ism” it opts for is environmentalism — not pan-Shiism, Sunnism, Turkism, Kurdism or Islamism.