I'd far prefer you stealing Roosevelt's worker, his lands, his capital and his life.Given BalbanesBeoulve's insight on Sury (thanks for that, obviously the fact I've never started on the same continent with him before explains my ignorance), it might be wise to keep Roosevelt as a friendly buffer.
This map seems to be very favorable - I humbly believe it's time to get ambitious! Why not take this excellent shot at ending your Emperor stint with a new record score? A free worker would be a definite help. There seems to be enough neighbors - you don't need the American for the vital tech trade.
And regarding the ugly-evil-alien-guy, wouldn't this be a perfect opportunity to showcase your protective trait?

Meaning that if you include Washington and environs in greater Arabia, you seem to have all the land you need, so you don't need to invade Khmer right away.
That's a perfect opportunity to have a defensive war, where Ugly Evil squanders his economy by uselessly suiciding his armies against your defenses.

It sure would be more interesting than Plan A (letting Roosevelt do your dirty work behind the scenes) and it would provide some action where normally the bountiful lands would dictate a peaceful game.
This way you'll use Surys alien demands against him. Turn him down, watch him get mad and let him bleed himself dry, I say!!

Only thing is you need to make sure to win the war for the hearts and minds of the populations of the landmass (aka religion) - but Saladin would only see that as an additional challenge, wouldn't he?
