Complex sentence: In the modern age, after the decline of ideas such as the divine right of kings and with the rise of nationalism, Terrorism more often involved anarchism, nihilism and revolutionary politics, but since 1980 there has been an increase in activity motivated by religion.
Split into simpler sentences: In the modern age, after the decline of ideas such as the divine right of kings and with the rise of nationalism, terrorism more often involved anarchism, nihilism and revolutionary politics. Since 1980 there has been an increase in activity motivated by religion.