The Triple Alliance Between England, France and Russia
Facing the rising German influence in the Middle East, the English tried and managed to close their long and significant disputes with the French and the Russians, in order to form an alliance against the Germans and their allies. The major disputes between the French and the English concerned their colonies in Africa (see the following map).
At the beginning of WW1, France was controlling almost all of West Africa (yellow colour), and England was controlling almost all of East Africa (red colour), and therefore Africa was a source of disputes between the English and the French.
However when confronted with the German "threat", the French and the English rushed to close their disputes with a series of agreements known as "Entente Cordial". As you can read at the following Wikipedia link, with Entente Cordial in 1904, England and France closed 1000 years of disputes and wars.
https://en.wikipedia.org/wiki/Entente_cordiale
Among other things, with this agreement England accepted France"s control over Morocco, which was crucial for controlling the Straits of Gibraltar, and France accepted England"s control over Egypt, which was crucial for controlling the Suez Canal (see lines 1 and 2 on the following map).
Moreover, with their alliance with the English and the Russians, the French were hoping to take their revenge for their defeat from the Germans in 1871, and regain control of the rich in iron and coal area of Alsace and Lorraine, which was lost during this war. Coal was in the 19th Century what oil became in the 20th Century, and even the navies were using coal, until coal was finally replaced by oil in the early 20th Century (1900). Indeed after the defeat of the Germans in 1918, the French regained control of Alsace and Lorraine.
Moreover, with the Sykes-Picot Agreement, the English promised that in case of victory they would offer the French some of the Ottoman Empire territories. According to this agreement, England would take the oil rich Iraq, and France would take Syria. Actually there was no Iraq and Syria at the time.
The Ottoman territory that would be taken by the English with this agreement was later given the name "Iraq", and the Ottoman territory that would be taken by the French with the same agreement was later given the name "Syria".
This is the reason that the members of the ISIS army (Islamic State of Iraq and Syria) are saying that they are destroying the Sykes-Picot Agreement by reuniting Syria and Iraq. You can see the Sykes-Picot Agreement on the following rough map.
You can also read about the Sykes-Picot Agreement at the following Wikipedia link.
https://en.wikipedia.org/wiki/Sykes%E2%80%93Picot_Agreement
Moreover with the Anglo-Russian Entente in 1907, the English and the Russians closed their centuries"
long disputes for the control of Central Asia and the Middle East (Iran, Afghanistan and Tibet). You can read at the following Wikipedia link, that in 1907, the English and the Russians agreed to split Iran, Afghanistan and Tibet in spheres of influence.
https://en.wikipedia.org/wiki/Anglo-Russian_Entente
The agreement between the English and the Russians allowed them to stop antagonizing each other and turn their attention to the Germans and the Ottomans who were a threat for the control of the Persian Gulf and the Caspian Sea.
However from their alliance with the French and the English, the Russians did not simply expect to protect the oil rich Caspian Sea region from the German and Ottoman threat, but were also hoping to gain control of Constantinople, the Bosphorus Straits and the Dardanelles, which were controlled by the Ottomans, and which would give the Russians uninterrupted access to the Aegean and the Mediterranean Seas (see maps below).
At the following Wikipedia link you can read that with the Constantinople Agreement, the English, the French and the Russians, agreed that in case of victory, Russia would take control of Constantinople, the Bosphorus and the Dardanelles.
https://en.wikipedia.org/wiki/Constantinople_Agreement
However even though the allies did finally win the war, Russia did not get Constantinople (today Istanbul), because Russia collapsed in 1917 and exited the war, since she entered a painful civil war between the tsarists and the Communists.
By agreeing with the Russians to split Iran into spheres of influence, the English would gain control of the Persian Gulf while the Russians would retain the undisputed control of the Caspian Sea, and together they could fight the Germans and the Ottomans. You can see on the following map that Iran is the region between the Persian Gulf and the Caspian Sea, holding itself a very large amount of oil and natural gas reserves. Iran is the second and fourth richest country in the world in terms of natural gas and oil reserves respectively.
However at the time most of the region"s oil was coming from Iraq and Baku, since oil in Iran was only discovered in 1908.
The Anglo-Franco and the Anglo-Russian alliances, together with the Franco-Russian alliance, encircled Germany and her allies (see following rough map).
