This is the subsector as presented in Traveller: The New Era. I have checked the information against the Regency Sourcebook, and it should be correct.
The Darrian Confederation is in a very difficult
position. Their close ties with the Regency has ensured their survival.
But as the Sword Worlds have disintegrated (and almost entirely annexed
by the Regency), and as the Zhodani Consulate is imploding, the Regency
is now the greatest threat to the independence of the Confederation.
This is putting unexpected strains on the Daryens as they attempt to maintain
a good relationship with the Regency, but to also chart a course that ensures
their own survival. And any such course requires expansion.
As part of that expansion, the Darrian Confederation annexed Ator (in addition to Condaria and Nonym, which joined earlier). They also tried to wrest Uniqua away from Garoo, but were fought to a stalemate. As a result control Uniqua is split between pro-Garoo forces, pro-Confederation forces, and independent forces that just want them both to go away.
Garoo realized that they would never be able to stop the slowly advancing Confederation. Because of this, the War Council swallowed their pride and took the only avenue they saw available to them and became a client state of the Regency. As a consolation, the Regency placed a Naval base on Garoo.