It's very doubtful the US will bomb Egypt over that, it didn't even bomb Egypt when it was directly involved in wars with Israel. Currently the Egyptians are in violations of the peace agreements with Israel over stationing military forces in Sinai, yet no bombs are falling.
Generally I think they targeted the US because of Islamist Ideology.
Islamism links conquest and imperialism to a proof of the religious validity of Islam.
Once the West has begun its control over Arab countries the idea in the 1920s has emerged where the reason why Islam lost its prominence is because they lost the "true" islam. Therefore the solution is to return to medieval Islam, similarly to fascism nostalgia to the Roman/German empires.
In that context, even the fact that the United States exists as a cultural force and influences arab teens to wear jeans is a major threat. Don't be naive that it is all over Palestine, Islamism started prior to the existence of Israel.
>Generally I think they targeted the US because of Islamist Ideology. Islamism links conquest and imperialism to a proof of the religious validity of Islam.
You don't have to speculate. You can actually just look at what the bombers stated the purpose of their attack was. It wasn't part of a conquest; it was an attempt to punish us for our history in that region, with a very specific policy of ours mentioned explicitly by many of the masterminds of 9/11.
The only Islamist movement seeking conquest in recent history was ISIS, which is why a lot of their attention was spent expanding their caliphate into their neighbors' territories rather than launching quixotic attacks at the US on our soil. I'm not including ISIS-K in this assessment, as they glow more than Langley.