Poland’s ruling nationalists signed a new coalition agreement on Saturday, ending weeks of in-fighting in the three-party alliance over how it will govern over the next three years. The leaders of the Law and Justice (PiS) party and the smaller conservative United Poland and Accord groups signed the deal at PiS headquarters in Warsaw on Saturday but gave no details on how the coalition will work in practice. “I am absolutely sure that these years will be beneficial for Poland. This agreement guarantees that,” Jaroslaw Kaczynski, the head of PiS and Poland’s de facto leader, told a news conference that was also attended by the leaders of his two smaller allies and by Prime Minister Mateusz Morawiecki.