Slevokxian spy rings in the AC are viciously hunted down and summarily executed. A general warning is sent out that any person in the AC or out of it that attempts to harm an AC citizen or the AC government will be executed.
Meanwhile, terrorists backed by the AC engage in a series of political assassinations and strategic bombings in several major Slevokxian cities. They are also commissioned to turn the Slevokxian people against their government, or to put them in a state of total fear.
Supersonic is no big deal. The AC has supersonic jets as well, and plenty of missiles are supersonic as well. Your UFOs are shot down by missiles fired from supersonic jets.
AC submarines engage in the systematic sinking of any Slevokxian ships, military or otherwise. Great pains are taken not to sink neutral ships.
The AC's missile interceptor grid and general air defense grid are both given substantial upgrades.
A massive wave of supersonic jets flies over the Slevokxian capitol, and with many losses, drops capsules containing napalm, white phosphorous, sarin, and regular explosives. Much of the city is destroyed. Other jets fly over agricultural areas dropping salt and napalm.
A bounty of $1,000,000,000 is put on the head of each premier of Slevokxia. An extra 50 million will be paid if a Slevokxian does it. The AC puts out a reward of $100,000 to any Slevokxian soldier willing to desert and join anti-Slevokxian rebels/guerrillas/terrorists. The AC is super rich, so it can afford this easily.
The Grand Sheikh and his family relocate to a secure location. They leave the Imperial Palace by way of secret underground passages, and literally no one but the Grand Sheikh and his company (including loyal bodyguards) has a clue where he is.
Slevokxia doesn't seem to have any noteworthy oil reserves. The AC recommends that all nations embargo trade, especially of steel, titanium, and oil with Slevokxia. The AC will buy whatever supplies would have gone to Slevokxia at 1.25 times the Slevokxian price. Such nations as do this will also be granted favorable trade scenarios with the AC in future.
The last Slevokxian soldier in Sinai is shot near Aqaba.
The minute Slevokxia stops fighting and releases Sinai is the minute all this stops.
I'd also like to point out how hopeless it is for Slevokxia. Your nation has been split more or less for a while, it's only recently been unified. You've had to fight jungle rebels. You have little in the way of oil reserves or construction materials for such things as planes or ships or tanks or anything.
You're fighting the AC, which is allied with Belsnia, Erinaum, and Klevinstein. These nations are fully equipped and up to date in both military and other technologies. The total population, land mass, resource production, and general military force of the Triumvirate is far greater than anything Slevokxia can front. Surrender of Sinai is no great loss for Slevokxia which hasn't even developed it save to position troops there.
You fight a war such as the Southern Confederacy did against the north, or Japan did against the United States. Make it easy on yourself and end it before your nation is irreparable.
Goodness this is long.