After almost 15,000 killed in Syria's civil war, now in its second year, there is no clear end game.

One side of the political spectrum is urging U.S. President Barack Obama to go into Syria -- and do something. What isn't quite clear.

The realpolitikers, seeing that Russia and China aren't asking Syrian President Bashar Assad to walk the plank, are urging maximum caution.

Former national security adviser Zbigniew Brzezinski said if Turkey, Syria's neighbor to the north, Saudi Arabia, and other Arabs "support a course of action that they think is needed for resolving the Syrian problem," the United States will "fully support" it. But he also made clear that Syria isn't Libya and Assad isn't Moammar Gadhafi.

Standing next to British Prime Minister David Cameron in the Rose Garden, Obama said that while the U.S. military plans for everything, the United States and Britain will confine their coordinated actions to diplomatic and political pressure.

Except for a handful of superhawks, most of the Mideastern hands in Washington, on both sides of the aisle, realize Obama isn't about to get the United States involved in another war in the very heart of the Middle East while still at war in Afghanistan.

President George W. Bush ordered the invasion of Iraq in 2003 while still at war in Afghanistan. And today, any Iraqi official will tell you, not for publication, that Iran has far more influence in Baghdad than the United States.

Henry Kissinger injected a timely history lesson. In his syndicated Tribune Media Services column, he brought up to date the 1648 Treaty of Westphalia on the inviolate nature of the nation state.

"Does America," he asked, "consider itself obliged to support every popular uprising against any non-democratic government, including those heretofore considered important in sustaining the international system? Is, for example, Saudi Arabia an ally only until public demonstrations develop on its territory?"

"If the objective," Kissinger writes, "is confined to deposing a specific ruler, a new civil war could follow in the resulting vacuum, as armed groups contest the succession, and outside countries choose different sides."

Those who say let's-do-something/anything-to-show-that-the-free world-cares are chiefly concerned with depriving Iran of its key Middle Eastern ally, a laudable objective. Our Saudi and Qatari friends are helping the Free Syrian army so why shouldn't the United States?

For Tehran's superannuated theocrats, Syria, dominated by the secretive minority Alawi Muslim sect, is Iran's gateway to Lebanon and its Hezbollah ally, and its Hamas ally in Gaza.

One of the many problems in siding with Syria's armed opposition is that it's not made up of Western-oriented democrats but more of a heterogeneous group that encompasses Islamist extremists and pro-al-Qaida elements that are far more anti-Western than Assad's regime.

Assad himself was an eye specialist in London when his father died at 69 in 2000 after three decades of a brutal one-man dictatorship. Prior to Assad father's rule, Syria experienced 21 coups since the end of the French mandate in 1945. Total loyalty to the regime was the only criterion in what otherwise was a semi-capitalist economy. Syria became a client state of the Soviet Union and has remained an important arms market for Russia since the end of the Cold War.

After the Iraq disaster, where Iran now has more influence than the United States despite a $1 trillion, almost 9-year war, Obama and the Joint Chiefs of Staff are understandably reluctant to get involved; NATO allies are even more reluctant.

Recent reports of the United States and Israel working together clandestinely in cyberwarfare attacks against Iran's nuclear installations add another unknown to the strategic equation.

Iran and Russia have strong ties to the Assad regime. Yet some conservative hawkish voices argue the Libyan operation could be repeated in Syria. But it is infinitely more complex. It also has the makings of a Spanish civil war scenario (1936-39) with the great powers aligned by proxy against each other -- Hitler and Mussolini against Stalin and Stalin lost. And half a million were killed.

Syria also evokes shades of Lebanon's long civil war. The Muslims versus Christians bloodshed lasted 10 years (1975-85) and killed 150,000. Syria, under the President Hafez Assad, first sided with the Christians before switching to the Muslims.

In 1978, the Israelis entered the Lebanese fray to attack the PLO guerrillas up to the Litani River. Four years later, June 6, 1982, responding to more Palestinian attacks, the Israeli army, under Defense Minister Ariel Sharon, invaded Lebanon with a massive force that drove all the way to Beirut where Lebanese Christians cheered their arrival.

This triggered a U.N. decision to dispatch to Beirut a multinational peacekeeping force, including U.S. troops.

Sept. 16-18, 1982, atrocities in two Palestinian refugee camps in Beirut -- Sabra and Shatila -- whose only access was controlled by Israeli troops resulted in Lebanese Christian Phalangist militia, Israeli allies, slaughtering 1,000-3,500 Palestinians.

Israeli troops didn't pull back from Beirut till May 1983.

A few months later, Oct. 23, a Mercedes truck laden with 12,000 pounds of TNT crashed into the U.S. Marine barracks near the Beirut airport, killing 241 in their sleep, the deadliest single-day death toll for Marines Corps since the Battle of Iwo Jima in World War II. Two minutes later, a similar attack killed 58 French paratroopers.

Hezbollah, Lebanon's Iranian surrogate, was behind the attack. And behind Hezbollah was Mostafa Mohammed Najjar, who was in command of the Iran's Revolutionary Guard expeditionary force in Beirut in 1983. He became Iran's defense minister in 2005.

These are all recent history lessons. Lest they be forgotten by Washington's more recent armchair strategists.