re: Shuttle shutdown savings?: Griffin or Zubrin
Hmm, here'a previous post.
If the US goes it alone and deliberately won't want cooperation, then it will completely depend on US policies which change faster than elsewhere.
The US has been bashing against Russia for its late Zvesda delivery, but it's thanks to Russia there still is a US presence in space, in spite of no Shuttle flights. Also, international treaties force the respect of commitments (if later ones are also hoped) and Griffin must be aware of this.
The ISS or at least permanent human presence in LEO is not a past endevour. There still are plenty of things to do there and not just government related.