WASHINGTON — The defeat of the Kaczynski twins' Law and Justice Party (PiS) in Poland brought sighs of relief across Europe. But, as Donald Tusk's new government assumes office, it is important to learn the lessons that their defeat holds for all of us.

Many governments waste good economic times by postponing the reforms needed to build a prosperous future. The PiS-led government, elected in 2005, inherited a fast-growing economy, but did nothing to strengthen that legacy. Instead, privatization was blocked, while fiscal reforms and deregulation remained paper proposals.

Indeed, the Kaczynski government embarked on a program of antireform. The separation of powers (an independent judiciary and central bank) was undermined in favor of a "strong" state. The PiS captured the public media; the general prosecutor's office was politicized and, with the use of the media, was turned into a tool of party propaganda aimed at showing that Poland was ruled by malicious hidden forces that cheated Poles and kept them poor.