The global conflicts of the 20th century were not the result of nations’ fights against one another, but a clash of imperial powers vying for supremacy. In World War I, the fight was between the challenger, Germany and Great Britain and its allies as guardians of the status quo.
By 1917, this evolved into two conflicting global missions: the American-type Liberalism (Wilsonism) and the Soviet-type Communism (Leninism). In World War II, Germany again made an attempt for hegemony (this time justified by a more atavistic, racial supremacy), but its efforts had been denied by two powers emerging on either end of the continent, Europe.
The second half of the 20th century was a time of the Cold War, with two competing ideologies facing one another in relative stability.
As of 1991, the United States – as the winner of the Cold War – began building a unipolar international order, challenged on two levels: in the form of two localized challenges by China and Russia and a global challenge of Islam.
Shortly after the onset of globalization, historians – such as Samuel P. Huntington – regarded it as a unified phenomenon surrounded by local conflicts. In the present, we are witnessing a halt in globalization and there is an increasing chance for a multipolar world gathered around civilizations coalescing around a regional power vying for hegemony.
Internal and external opposition to globalization has also given birth to a contrary trend, that of a more assertive representation of national interests, a loss of trust in international organizations and the rejection of global agreements.
The change we are now living is a result of the crisis of liberalism and everything modern is based on the rejection of liberalism to varying levels (non-liberal -> illiberal -> anti-liberal).
A growing importance of policies dictated by geographic reality, economic autarchy, the ethno-populism of indigenous European nations and the desire to preserve national identities are accelerating the demise of the liberal world order.