For those with short memories, the UK AEW force was declared to NTO as our contribution to the NAEWF in lieu of paying for the rest of the force and contributing crews.
One presumes that, in their absence, we will be having to pay our fair share of the costs for the remainder of the force and its use. I doubt there are any savings, and with the remaining duplication in infrastructure it probably absorbs additional cost, not a saving.
Not strictly true... Historically, the UK was to be part of the NAEW Force with 24 crews to be based at either Brize or Fairford (nothing decided) but the Nations could not agree funding so the UK pulled out of the multi-national programme and instead contributed our own national AEW as the UK Component. Britain does not pay anything into the NAEW Force - our contribution is to provide that UK Component. There is no penalty if we don't provide our aircraft (bearing in mind we were 9 years late to the party in the first place).