Nixon, perhaps energized by the multiple crises (the Yom Kippur War, the tapes war) acts quickly: just two days after Spiro Agnew resigned, he nominates House Minority Leader Gerald Ford for the VP vacancy. This, at least, was a pragmatic move designed to get someone confirmed. Unfortunately for Nixon, however, it also meant a president-in-waiting that no one in Congress worried about, which removed at least one important disincentive for eventual impeachment.
The fight that Nixon really wanted, however, was with the special prosecutor. Archibald Cox had just secured his first indictment (Egil Krogh, from the Plumbers). By the 12th, Nixon had already told Attorney General Richardson that with Agnew taken care of they could move to eliminating Cox; on the 11th, chief of staff Al Haig told John Connally that they were "going to fire Cox within a week or ten days."
Now on the 12th, with US and Soviet airlifts delivering supplies to the armies in the Middle East, the Circuit Court ruled that Nixon had to turn over the subpoenaed tapes to Judge Sirica. The pressure is building.