Declare. Time for breaking balls.
The Fleet flies to the nearest planet, and commences a semi-assault on the immediately largest ship.
The Type 3 Cruiser fires its Destabilization cannon, which immediately renders all systems on the one ship useless. (This is my fleet's thing. Note my fleet has flaws too. They're not that hard to spot.)
The fleet sends an aftwards communication....
Tumbria has also commissioned a public trade station to be built. It will be finished in 3 turns and upgraded every few passing turns.