Kaylons refused military co-operation unless the PU turned over the girl Moclan
The Moclans refused military co-operation to battle the Kaylons. But then the Orville crew learned more about the Kaylon history and discovered their deep hatred of biological life stemmed from their long history of enslavement and abuse at the hands of biologics. So the crew reconciled with the Kaylons, but ended up in a fight with the Moclans who joined the Krill to wage war on the Union, pretty much entirely unprovoked.
The alliance with the Moclans and Krill was ultimately always doomed, due to the natural ideological conflict between them and the Unions. The Kaylon were the natural allies, but only achieved this allegiance through good faith efforts by each of the factions.
The Moclans refused military co-operation to battle the Kaylons. But then the Orville crew learned more about the Kaylon history and discovered their deep hatred of biological life stemmed from their long history of enslavement and abuse at the hands of biologics. So the crew reconciled with the Kaylons, but ended up in a fight with the Moclans who joined the Krill to wage war on the Union, pretty much entirely unprovoked.
The alliance with the Moclans and Krill was ultimately always doomed, due to the natural ideological conflict between them and the Unions. The Kaylon were the natural allies, but only achieved this allegiance through good faith efforts by each of the factions.