Morroco

TAP flies from Fez to Lisbon, so that would work with a stop in Lisbon. If you are willing to travel a bit further, Air France, Lufthansa, Iberia and Alitalia flies to Casablanca (so does TAP as well). But what it will look like after the pandemic is a good question.

Royal Air Maroc is currently running 3 times weekly non-stop Casablanca/Dulles; you could then connect to destination.

Assuming that flight schedules return as before the pandemic, and since British Airways served Sea-Tac, like they did Denver, I’d think this would work for you. We flew British Airways from Marrakech home to Denver, connecting thru London. Took Air Arabia to get from Fes to Marrakech.

The full flight report for the trip was: starting with British Airways from Denver to London to Marrakech. After staying several days in Marrakech, we flew to/from Fes on Air Arabia. After returning to Marrakech, and then a desert tour over several days, we flew home British Airways on the return portion of the round-trip ticket. Maybe you weren’t planning on time in Marrakech, but it was fantastic, too, and at the very least was the way we got to/from Morocco, with Air Arabia part of the process.

You can fly from Fes to Casablanca then nonstop to New York and Washington DC.

I've used Air France to fly to Morocco, with a connection through Paris and returned home through Paris as well. My husband has also used Royal Air Maroc. In the pre-pandemic days, they had a nonstop flight from JFK to Casablanca. It could be that currently published schedules are a mess because of the pandemic so unless you are planning to go now, you should probably wait until things are bit clearer to check on flight schedules.

No offense, but spelling the country correctly will help searches. Then use a tool like Google Flights. I will say, I still prefer the old webiste MatrixITA, wich was the old travel agent flight tool. They don't sell tickets, so they offer more airline options than something like Expedia.
Looking during covid also means looking at several different arrival and departure cities. Casablanca is the obvious major city for the 2 cities mentioned above, but what about flights from Marakkesh. For something a bit out of the box, what about continuing north to Tangiers and taking the ferry to Gibraltar and home from there. Certainly not an efficient option, but could be an unexpected adventure.
Royal air Maroc flies from Fes to Paris, but airport doesn't get great reviews.

You can fly from Fes to Casablanca then nonstop to New York and
Washington DC.

If you want to add some time in Casablanca you can also take the train from Fez. Don't underestimate Moroccan trains.

Royal air Maroc flies from Fes to Paris, but airport doesn't get great
reviews.

That is also an option, but Royal Air Maroc flies to Orly and most transatlantic flights use Charles de Gaulle so that might involve changing airports.

I believe we flew home (SFO) from Casablanca on Air France (Delta?), with just one change, at CDG. You might also check on routes originating in Rabat. We had been on a tour that ended in Casablanca, which dictated that departure site; however, I wouldn’t go there, otherwise. Personally, I’d rank fewer stops very high among my choice criteria.