How far, would you say, was the Reformation responsible for domestic and international changes?

The Protestant Reformation of the 16th century was nothing less than a religious revolution in Europe. It had international consequences for the states of Europe as well as for the religious practices of common people.
One important result of the Reformation was religious warfare between Catholics and Protestants. This conflict dragged on for many decades. The last great conflict in which religion played a key role was the Thirty Years' War (1618–1648).
A second result that had international repercussions was the Counter-Reformation or Catholic Reformation. Corruption and ineptitude in the Catholic Church had helped cause the Protestant Reformation. The Catholic sale of indulgences and other immoral actions had opened the door to Protestantism. In the mid-16th century, the Council of Trent met, under the pope's auspices, to reform the Catholic Church. The Council of Trent shaped the Catholic Church of today.
A third result of the Protestant Reformation was that it brought many Protestant worshipers closer to God. Protestants were able to read the Bible in their own language. Before the Protestant Reformation, all Bibles were written in Latin. Literacy rates went up as more and more people read the Bible. In the various Protestant churches, the divide between clergy and laity was far less pronounced.