He is actually an Israeli. His real name is Yair Lotan.
Israeli-born Yair (Jonah - stage name in USA) Lotan...
Jonah starred in the Keira Knightley film The Jacket.
Jonah previously appeared in the British detective series Foyle's War, London/New York cross-over show Ny-Lon.
Jonah joined the cast of 24 for it's fifth season; he plays Spencer, the love interest to fan fave Chloe.