Originally Posted by PhilH

Simon, I reckon you're best off with AA. You don't necessarily want to start with a *A carrier, as you won't have any status. Also, knowing your normal route is to Moscow, then there aren't many good *A options. With AA you can just put surplus miles each year (after reaching 3,500 TPs) and you'll have the advantage of

a) much better mileage redemption rates on AA
b) ability to buy more miles on AA to top up your account
c) lifetime Sapphire
d) even if they do leave OW, you can still use the miles for internal US flights(indeed if they DID leave OW then that would be your only option as BA miles would not be useable)

Seems to be the best option to me.