The speech

 The President conceded, perhaps not in so many words, that the speech would not defeat Daish and its allies.
It had been preceded by days of expectation and commentary, and the actual contents had no surprises.
No doubt we'll be reading about it for days, and perhaps years
Among the issues to be tested are to what extent can the United States achieve its objectives with air power, or by reliance on Muslim allies to do most of fighting on the ground?
The Muslim countries included in what the President calls his 40-country coalition are those whose people have shown varying degrees of support for Islamic extremism, including some--like Saudi Arabia--whose governments have sent substantial funds to groups that were extremist from the beginning or crossed the borders into extremism.
What will come from the President's indication that US air power will operate in Syria, and whatever that means for cooperating with the military and government of Bashar Assad. By already cooperating with Assad's allies Iran and Hezbollah, the President has moved from the simplicities of American ideals to the complexities of the Middle East.
Within hours of the speech, we were hearing from Syrian opponents of Assad, insisting that the American President follow their lead in the morass of Muslim politics and mutual hatreds. Involved here may be assertions that--on account being Alawites--Assad and his  regime are not true Muslims, and must be opposed as infidels.
Other governments, supposedly in the coalition, were more generous with words of general support than commitments of military activity.
Turkey's government announced that it would not take part in combat, and would not allow aircraft to take off from its soil in order to attack Syria or Iraq. It would limit its participation to the supply of humanitarian aid.
It remains an open question whether Turkey will police its borders in order to keep additional thousands of European and North American Muslims from passing through it to  join Daish forces in Syria.
A prominent feature of Obama's policy would be airstrikes against Daish assets in Syria, where they are more prominent than in Iraq. However, Syrian authorities said they would shoot down American aircraft operating in their airspace.
From Iran's Foreign Ministry:

"The so-called international coalition to fight the ISIL (Islamic State) group... is shrouded in serious ambiguities and there are severe misgivings about its determination to sincerely fight the root causes of terrorism,"
Russia is somewhere in the coalition against Islamic extremism, while the US and European coalition members are involved in sanctions against Russia on account of Ukraine.

This speech may also be parsed as at least a partial abandonment of Obama's 2009 Nobel Prizewinning speech in Cairo, where he elevated democracy and equality to the pinnacle of what he wanted in the Middle East. Sometime later, he abandoned Hosi Mubarak as too authoritarian. Now he is sending Americans to fight alongside of Syrians, Iranians, Iraqis and Saudis, who make Mubarak's regime appear in comparison as an ideal of what is humane and inclusive.  
Obama's recent blessing of the new Iraqi President Fuad Masum  has yet to be tested for the openness to ethnic and religious inclusiveness that led Obama to work against his predecessor who gave too much to Shiite and too little to any other group.
Will Iran's cooperation in fighting those more extreme that it earn concessions--explicit or implicit--from Obama with respect to its nuclear program?
The President concedes that it will take years to eradicate Daish. Skeptics wonder if any movement based upon religious fanaticism and showing an attraction for Muslims in Europe and North America can be eradicated. Diminished or limited may be the extent of what is possible.
The speech reminded me of hearing John F. Kennedy more than half a century ago explaining that it was necessary to send more advisers and air crews to help the South Vietnamese combat the Viet Cong, with assertions that the Americans would avoid combat. Later came the report that Kennedy's people were involved in the murder of South Vietnam's undesirable president. By the time the Viet Cong had taken control of the entire country, more than 55,000 American service personnel had died.
Obama's concern to keep American boots off the ground, except as advisers and trainers of local forces, may not survive any longer than Kennedy's. Muslims will be asking themselves why they must risk their lives for America's war.
Among the issues that historians will ponder is what triggered Obama's shift over the course of his presidency. Was it the gruesome pictures of journalists losing their heads? The indications of genocide, sex slavery, and wholesale killing of prisoners filmed as Daish moved through Iraq? Or a more thoroughgoing realization that the West was at war with forces rooted in Islam, even while it remained forbidden to express that so bluntly?
Getting the various allies to work together as the Americans want will not be easy. Europeans along with Russia, Saudi Arabia, Jordan, Egypt, Turkey, Lebanon, Qatar and other Gulf entities have their own national agendas. Some are engaged in conflicts with one another, and several of their leaders have expressed doubts about a President they have seen to be unreliable on other occasions.
New York Times analyst accepts, for the time being, the President's commitment to avoid using American ground troops, and takes the President at his word that it would be a long and difficult struggle.

(Obama) "may have ensured that he would pass his successor a volatile and incomplete war, much as his predecessor left one for him. . . . the widening battle with the Islamic State in Iraq and Syria will be the next chapter in a grueling, generational struggle that has kept the United States at war in one form or another since that day 13 years ago . . .  when hijacked airplanes shattered America’s sense of its own security. Waged by a president with faded public standing, the new phase will not involve many American troops on the ground, but seems certain to require a far more intense American bombing blitz than in Somalia or Yemen."

Israelis are applauding this version of Barack Obama, while wondering about what will happen by way of implementation and success. The speech expands the concern of the US, and most likely its European allies for the problems associated with Islam. Left undone, of course, is joining Israel's reluctance to accept another Muslim state on its borders, or accepting Israel's equivalence between Daish and Hamas.
An early test will come with elections for the US House and Senate. A week before the speech, the projections were for a rejection of the President's party on both domestic and foreign issues, with a growth in the Republican House majority from a 34 seat to more than a 40 seat advantage, and with Republicans winning a six seat majority in the Senate.