John Levine writes:

Haven't seen Amex with a proximity card yet, though will be sure to keep
an eye out.

I have one in my wallet, issued in the U.S.

My UK Amex has no chip at all, but they say that when they send me a new
card next month, it'll be chip+pin.
Amex were painfully slow introducing chip-and-pin in the UK. But have a
had a corporate amex with a chip for a while now, the lack of
chip was becoming a pain as I was unable to use pay-at-pump or automated
(railway) ticket machines, you know the sort of thing business
travellers need.

Phil