Who should battle radical Islam?

If radical Islam truly is the greatest threat faced by civilized people, then all should join in opposing it with all the means at our disposal.
However, it is Muslims that are the major targets of radical Islam, and westerners have a poor record in pacifying the Middle East.
Muslims are divided. The Shiia-Sunni conflict remains dominant into its second millennium, now at a peak of intensity. It pits Iran and Shiite militias in Iraq, Lebanon, various Gulf Emirates and Saudi Arabia against the Sunnis of those countries along with Egypt and Turkey. 
Governments of countries where Sunnis are dominant pursue national goals as well as looking out for Sunni interests. The Islamic State is Sunni as well as radical, and this produces a situation where Saudis are both aiding and opposing Islamic State as well as other Sunni jihadist militias. Saudi Arabia's conflict with Iran and its allies in Yemen also limits what it contributes to opposing Assad and his Shiite allies in Syria. Egypt with its Sunni majority is principally concerned to battle Sunni extremists in the Sinai, and to keep the Sunnis of Hamas and other Jihadists bottled up in Gaza. Turkey is embroiled in domestic as well as international conflicts. It remains in NATO, is a doubtful candidate to join the European Union, and is a major station on the refugees' routes to Europe.
How much should Americans, Europeans, Russians, and Israelis bleed for the sake of dealing with militias that are roiling and confusing Muslims across the Middle East?
Only as much as they must.
For Israel, this means keeping serious weapons out of the hands of likely enemies, being ready to respond in border regions of Syria and and Lebanon, and to punish Hamas and its allies in Gaza, yet again, when necessary. 
Reports are that Israel has been able to use its connections with Russia and discussions about what each will do in Syria to delay Russia's transfer of sophisticated weaponry to Iran, on account of their likely transfer on to Hezbollah. Americans thinking of a renewed Cold War may not be happy with Israel-Russian contacts, but little countries have to look out for themselves.
The US is limiting itself to attacks that do not endanger large numbers of its personnel, which makes sense in light of heavy losses with minimal accomplishments from Vietnam through Iraq and Afghanistan. While Obama is getting flak for his timidity, to his credit are targeted assassinations of key Islamic personnel, including what is said to be the first presidential decision to assassinate an American citizen since the Civil War, directed against an American turned jihadist in the Middle East.
Europeans are contributing to air actions against Islamic militias in Syria and Iraq, and dithering about uncountable Muslim refugees already among them, at their gates, or heading in their direction.
Russians have several concerns with the Middle East, affected by substantial parts of their own territory and population that is Middle Eastern. Moscow has suffered as much as any western city (except NY on 9-11) from Muslim terror.
Intelligence, i.e., military and political information about adversaries, is crucial. However, it is hard to be sure about what is thought to be known across the borders of language, religion, and culture. Americans have been fond of praising the wizz kids of Secretary of Defense Robert McNamara, the CIA and NSA, and elite military units. Against the claims of bringing down Saddam Hussein and Osama bin Laden are American casualties and far greater casualties among foreign civilians, then withdrawals short of success from Vietnam, Iraq, and Afghanistan. The latest story of careful analysis and absolute flop is associated with the Hillary Clinton-Barack Obama moves to join Europeans in attacking Qaddafi's regime in Libya, and the ongoing civil war left behind.
The US, European governments, Russia, and Israel have enough to do in dealing with Muslim extremists at home. Concerns for the freedom of religion and free expression, and the difficulties in controlling what is available on the Internet assure the need for constant vigilance against domestic violence fueled with religious intensity. Intelligence agencies are doing what they can to identify individuals preparing for recruitment to the Islamic State or other jihadist militias, and to arrest those who serve, survive, and return home.
The lack of concerted US and European action may delay for years the defeat of radical Islam. We should count on being threatened for the indefinite future. However, the combination of western bombing and Muslim fighters has caused the Islamic State to lose  ground, fighters, and resources in Syria and Iraq, even while neither place is anywhere close to the unified state it once was. Radical Islam and a variety of militias of unclear loyalties and intentions seem likely to characterize the Middle East for some time, threatening mostly Muslims, and working against the likelihood that they will emerge from the backwardness of politics, economics, and culture.
Also in the calculations of Americans and Europeans to limit their direct participation in the Middle East is the stimulus that their troops provide to the Islamic drive against infidels seeking to reestablish colonial control. Anti-western campaigns include both politics, i.e., anti-colonialism, and theology, i.e., opposition to infidels who haven't accepted the true faith, or the true version of the faith, whether it Sunni or Shiite. 
Overall, it seems best for western governments to concentrate on limiting the extremism and violence coming out of already established Muslim communities in western countries, and to deal with the knotty issue of all those additional Muslims who want refuge.
Comments welcome
Ira Sharkansky (Emeritus)
Department of Political Science
Hebrew University of Jerusalem
[email protected]