My thought was that blocking the canal would cut off a major source of revenue for Egypt.
AQ would consider this excellent news. Millions of young Egyptian men, all muslims of course, will be angry at the USA and will sign up en masse as suicide bombers, foot soldiers, and every other kind of AQ helpers.
Hurting them in the wallet works only with economy-oriented societies, such as democracies (who rise and fall on news from stock exchanges) and dictatorships (who always complain that the last palace is not fully gilded yet.)
A theocracy of 6th century does not want money. Furthermore, money is dangerous to it because it separates people into classes and creates private interests. Egyptian computer scientists would want different things than egyptian goat herders. Fundamentalists want everyone to be illiterate goat herders; the only skill worth having is how to make IEDs. This is exactly why Communists were killing educated people in Russia, in China, in Cambodia... they couldn't allow smart competition.