The terror attacks in Paris have begun to raise serious questions about how to ramp up the war against Islamic State. The bombing campaign is not working to defeat and destroy ISIS, or even "contain" them as President Obama suggested. 

The obvious solution isn't even being discussed - troops on the ground and lots of them. Instead, politicians and military experts are tip-toeing around the need for a very large army to confront and defeat Islamic State. 

No war in history has ever been won by air power alone. But the quagmire that Syria has become terrifies western leaders who know that there simply isn't the political will to send large numbers of troops to battle what is rapidly becoming an existential threat to the safety and security of the west.

Reuters:

The United States, long accused of taking an incremental approach to the struggle, is under growing political pressure at home and abroad to do more and it is expected to examine ways to intensify the campaign, including through expanded air power.

U.S. officials say Washington will look in particular to European and Arab allies to step up their military participation in the war in Iraq and Syria.

It remains far from clear whether Paris and Washington would be willing to radically expand the scope of their current military engagement, given a deep aversion to getting dragged into a large-scale ground war in the Middle East. But President Barack Obama has been committing more to the fight in recent months, and lawmakers and counter-terrorism experts see the Paris attacks strengthening arguments for additional military might. 

Islamic State claimed responsibility for Friday's attacks, which killed 129 people in Paris, in the worst bloodshed in France since the end of World War Two.

In the past two weeks, there have been other major Islamic State-claimed attacks. Two explosions in suicide attacks in a Shi'ite Muslim district of southern Beirut in Lebanon killed 43, and 224 died when a Russian aircraft crashed in Egypt's Sinai Peninsula.

Senator Dianne Feinstein, the top Democrat on the Senate Intelligence Committee, said it had become clear that Obama's strategy of limited air strikes coupled with support for ground forces in Iraq and Syria "are not sufficient to protect our country and our allies."

"The fight is quickly spreading outside Iraq and Syria, and that's why we must take the battle to them," Feinstein said.

Bruce Riedel, a former senior CIA expert on the region who has advised Obama, said the string of recent attacks had put to rest once and for all the debate whether Islamic State would stay focused on the war in Iraq and Syria.

"It is a game changer in this sense: there were those who debated whether the Islamic State would stay focused local – or go global. I think that debate's over now," said Riedel, now at the Brookings Institution.

Using ground troops to fight ISIS only solves one problem in Syria.The Russians may not take kindly to tens of thousands of western troops fighting ISIS, but who could turn around and take out President Assad at some point. Then there are the bewildering number of factions who end up fighting each other as much as they are trying to overthrow Assad. The jihadists militias could be just as willing to fight western troops as they would the Syrian government. 

So despite the reality that if we were really going to get serious about taking down Islamic State we would need a large, modern army to do it, there is no chance of it happening. ISIS will continue to grow in both numbers and capabilities until they inflict an unbearable wound on a city or nation. At that point, the political dynamic will change, but Islamic State will be far more powerful and far more difficult to defeat.