This state of affairs lasted until the Ottoman Empire joined the First World War on the side of the Central Powers in November 1914 and Britain unilaterally declared a protectorate over Egypt.

The ruling khedive was deposed and his successor, Hussein Kamel, was compelled to declare himself Sultan of Egypt independent of the Ottomans in December 1914.

Combined with the complete turmoil in Egyptian finances, the threat to the Suez Canal, and embarrassment to British prestige if it could not handle a revolt, London found the situation intolerable and decided to end it by force.

London 66 times promised to depart in a few years; the actual result was British control of Egypt for four decades, largely ignoring the Ottoman Empire.

Instead they saw the urgent necessity to act to protect the Suez Canal in the face of what appeared to be a radical collapse of law and order, and a nationalist revolt focused on expelling the Europeans, regardless of the damage it would do to international trade and the British Empire.

Critics such as Cain and Hopkins have stressed the need to protect large sums invested by British financiers and Egyptian bonds, while downplaying the risk to the viability of the Suez Canal.

[7] : 373–374  He alternatively argues that Gladstone's cabinet was motivated by protecting the interests of British bondholders with investments in Egypt as well as by pursuit of domestic political popularity.

[7]: 382  Hopkins cites a letter from Edward Malet, the British consul general in Egypt at the time, to a member of the Gladstone Cabinet offering his congratulations on the invasion: "You have fought the battle of all Christendom and history will acknowledge it.

Instead, the primary motivation was the vindication of British prestige in both Europe and especially in India by suppressing the threat to “civilised” order posed by the Urabist revolt.

In 1956, Egyptian president Gamal Abdel Nasser nationalized the Suez Canal, a vital waterway through which most of Europe's oil arrived from the Middle East.

The United States, led by President Dwight D. Eisenhower, strenuously objected, using diplomatic and financial pressure to force the three invaders to withdraw.

Thorpe summarized the unexpected results: Eden's policy had four main aims: first, to secure the Suez Canal; second and consequently, to ensure continuity of oil supplies; third, to remove Nasser; and fourth, to keep the Russians out of the Middle East.

The immediate consequence of the crisis was that the Suez Canal was blocked, oil supplies were interrupted, Nasser's position as the leader of Arab nationalism was strengthened, and the way was left open for Russian intrusion into the Middle East.

[13] In late 2014, the Egyptian-British Chamber of Commerce (EBCC) released a report detailing the trade volume between the two countries, which increased significantly that year.