At the outset of his richly detailed history of the Peloponnesian War, Thucydides, writing 25 centuries ago, warned, “What made war inevitable was the growth of Athenian power and the fear which this caused in Sparta.”

In this account of the Greek city-states at war, Thucydides – the greatest historian of the ancient world, perhaps of all time – unlocked the central reality of international politics.

International politics, unlike domestic politics, occur in an environment where actors –sovereign states – recognize no higher authority in securing their independence and interests. It is a raw contest for power and struggle for survival.

This unpalatable reality is willfully masked by the routine lip service paid to such ideas as international law, the role of the UN, or the utopian notion of one world government as the means for abolishing war and transcending international politics. But these ideas are as fanciful as wishing away gravity to fly like the imaginary Peter Pan.

The recent display by Iran, testing ballistic missiles that would place southern Europe, Israel and the U.S. presence in the Middle East within striking distance, gives the world notice once again of another unavoidable war looming in the region.

Iran’s nuclear ambition rolls forward undeterred since its secret facilities at Arak and Natanz were revealed in 2002. Despite attempts to bring these facilities – heavy water reactors and uranium enrichment plants – under International Atomic Energy Agency (IAEA) control, with the EU-3 (Britain, France and Germany) offering economic benefits and civilian nuclear technology to Iran as incentives for permanently halting activities, Tehran remains adamant in acquiring nuclear capability of its own.

Since 2006 the Security Council has voted several resolutions under UN Chapter 7 demanding Iran submit to the IAEA requirements. The most recent of these is Resolution 1803 of March 3, 2008, requiring Iran meet its international obligations.

Security Council resolutions, however, are toothless unless enforced. The cleric-based Iranian regime knows this, and has guessed the Security Council members, including the United States, likely will not authorize force to stop Iran’s nuclear activities.

This leaves Israel alone confronting Iran, which is ruled by men who do not cloak their anti-Semitic bigotry. President Mahmoud Ahmadinejad of Iran never misses an opportunity to broadcast support for “wiping out” the Jewish state.

There should be outrage at the UN that one of its member states openly espouses the intent of seeing another member state annihilated. The absence of such outrage is more evidence of how bereft the organization is of ethics and history, and of how little help in preventing war or, if the Iranian regime could get away with it, another Holocaust.

The world was warned in June 1981 when Israeli jets took out Iraq’s nuclear reactor, and again in September 2007 when they bombed a Syrian nuclear site under construction with North Korean assistance.

The international failure in checking Iran’s nuclear ambition will compel Israel to strike pre-emptively. This will be the result of abandoning Israel in the face of spiralling nuclear threat from a regime that is public in declaring its enmity against the Jewish state.

But such an Israeli pre-emption likely will unleash a dynamic of unpredictable consequences through a wider war and terrorism for the global economy dependent on Middle Eastern oil.

Thucydides would not be surprised, nor should we if we learned from him.