После долгих переговоров они смогли

После долгих переговоров они смогли достичь согласия и прекратили военные действия.

Результаты (английский) 1:

After long negotiations, they were able to reach agreement and cease hostilities.

Результаты (английский) 2:

After lengthy negotiations, they were able to reach an agreement and cease hostilities.

Результаты (английский) 3:

After long negotiations, they were able to reach agreement and to cease military action.