A French Objective
Since 1550, the growing trade with East Asian goods (although many were still forbidden, or at least scolded at) led people to think about a possibility to take out the middle man (the Seljuks in the South, the Russians in the North). In France, it was suggested that a conquest of the Sinai would allow them to sail the spice routes.
This idea changed the French politics toward the Seljuks. After the Great Seljuk War, the Seljuks had to cede the Sinai to France, which cut their empire in two. 1605, France started building many ships in Suez, making it a big trade center, started competing with Arabs for trade in the Indian Ocean.
After the anti-French War, the Seljuks got Sinai, Palestine and Aden back from France in the peace of Amsterdam 1694, but since Egypt had already separated from the empire, things weren't as they had been once.
France used the opportunity that the Seljuks had lost the Italian-Russian-Seljuk War, allied with Persia and stroke against the Seljuks in the fourth French-Seljuk War 1717-23. The French again occupied the Sinai and Aden.
1768, during the chaotic time of the French Republican Wars, Egypt used the opportunity and took French Sinai back. France was cut off from Asia again.
The Sinai would get a completely new fate in 1835: After anti-Jewish pogroms in North Africa, a delegation of rabbis approached the New Roman emperor Alessandro I. He offered the Jews a home at the Sinai, as close to biblical Israel as possible without moving right in, to form a buffer against the Persian empire and to guard the Suez Canal. This marked the beginning of the Jewish state.