BUENOS AIRES — One of the most dangerous moments in international affairs is when world powers seek to recover a portion of the power they believe they've lost.

After 2009, state actors (Russia, China, Iran and North Korea) and non-state actors (ISIS) became convinced that the United States was in decline and had abandoned the will to maintain its global primacy. They grew bolder with the assumption that Washington could not, or did not want to exercise political and military leadership on a global scale. President Barack Obama's budget cuts seemed to confirm this, as did the diplomatic formula of "leading from behind," his preference for multilateral initiatives like the climate pact, and his predilection for international institutions, dialogue and soft power.

North Korea has completed four nuclear tests and increased its missile launches (11 in total, including four in 2017), and boasts about the impending nuclear destruction of the West. Russia has violated the Intermediate-Range Nuclear Forces Treaty (INF Treaty) and reabsorbed some former Soviet territories. Iran has gone so far as to harass U.S. ships in the Persian Gulf. And China has been building naval bases in the South China Sea.

The Islamic State (ISIS), in the meantime, has killed thousands in Syria and Iraq, while also carrying out attacks in various western countries. The 2016 Global Terrorism Index found that 21 member states of the Organization for Economic Cooperation and Development (OECD) suffered terrorist attacks in 2015.

U.S. military actions in recent weeks are not the beginning of chaos, but a response to an increasingly chaotic world. Like them or not, they remind us of certain inherent lessons on the use of force in global affairs.

These are:

1) Utopian declarations only impress global elites and the international media. They mean nothing to revisionist states, which know that empires are faced down not on pulpits but in the battlefield, and are overcome with an effective offensive, not great eloquence. Deadlines, ultimatums and red lines must be backed with credible and decisive use of force, or they encourage defiance and invite aggression.

2) Use of force is an inalienable instrument of state power and war, a political act. Or, as the 19th century historian Carl von Clausewitz stated, the continuation of politics by other means. In today's world, it appears that the actors believe increasingly in the use of force and less in the elements that were supposed to replace or restrict it. We hear the terms "missiles," "threat" and "nuclear" much more frequently than "UN," "institutions" or "peace." This does not mean that the world is inevitably marching toward a third world war. But it does mean that in the current global disorder, states are increasingly relying on their own power.

3) Those with power will increasingly use force as a deterrent, for all the horror this may cause the progressive and liberal elites. Globalizing intellectuals despise war as a barbaric act and assume it to be the result of primitive warmongering, even as they praise agreements as the height of rationality and civilization.

Politics, like appeasement, isolation and collaboration, can often impede a particular crisis in the short term. But they doesn't necessarily solve the deeper causes of the crisis. The United States boosted its military spending in 2016 by 1.7%, China by 5.4%, Russia by 5.9% and India by 8.5%. For the realist in international relations, it is better to be ridiculed while effectively preventing a crisis than to be praised as you become more vulnerable and defenseless.

*Mariano Turzi is a professor of International Relations at the Torcuato di Tella University in Buenos Aires.

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