All seemed to agree that this time around, a red line had indeed been crossed and, therefore, based on solid evidence, some sort of coordinated effort should be made to make it clear to the Syrian government that this violation of internationally accepted norms would not go unpunished.

That unity has been shattered in the last couple of days. First, the Obama administration had to admit its intelligence does not tie Assad himself directly to the attack. It has strengthened calls on the president to first sit down with leading Democrats and Republicans and try to seek Congressional approval for any action. The absence of a “smoking gun” also put off many doubters wary of being manipulated. Finally, UK Prime Minister David Cameron did not manage to convince a skeptical British parliament, where many remembered how 10 years ago they were dragged into the Iraq War based on what later turned out to be false proof, to act.

The result is that in the public debate on Syria, in Turkey and elsewhere, we are back at square one. On one side, we have those who believe the killing of over 100,000 people is reason enough to intervene in Syria and who considered the chemical attacks to serve as an additional argument that might be the straw to break the camel's back. Again firmly opposed to this view is a mixed bunch of principled pacifists, old-fashioned anti-imperialists and a big group that simply does not believe military operations will be effective and could even be counterproductive. For that reason, they want all attention to be focused on the diplomatic initiative that was undertaken by Washington and Moscow some time ago.

Personally, I am convinced that any eventual progress at the negotiating table will only be accomplished after the military balance on the ground has shifted in favor of the rebels. Only then will Assad and his main backers, Russia and Iran, be willing to sit down and talk about a political solution. This is why I have been in favor for some time of supplying the non-jihadi rebels with sufficient arms and why now I support a military attack that will substantially weaken the Assad regime.

Several analysts have warned against the dangers of the limited bombing campaign US President Barack Obama has in mind. Even if the US would be able to stop Syria from using chemical weapons again, the war, in which most Syrians who died were killed by bullets or artillery and air strikes, will continue unabated. Assad will take his revenge on his opponents at home and abroad.

That is why two things need to happen once it has been established beyond doubt that the Syrian government should be held responsible for the use of chemical weapons in Ghouta. One is the destruction of the regime's military infrastructure and “command-and-control” centers, including the airports that are being used by Russian and Iranian military and commercial planes to offload new weapons for Assad. Secondly, we need a new American and European engagement to build up an armed opposition that can push back government forces on the ground but can also act as a reliable partner during negotiations and in the post-Assad era. As The Economist summarized its advice to Obama, “do it well and follow through.”

I fully realize that hitting Assad hard and supporting moderate rebels will not solve all the problems in Syria. It might create an even bigger mess in the short run. But what I fully reject is the conclusion that therefore doing nothing or staying out is the best option. As celebrated New York Times columnist Nicholas D. Kristof pointedly formulated it this week, “for all the risks of hypocrisy and ineffectiveness, it's better to stand up inconsistently to some atrocities than to acquiesce consistently in them all.”

Joost Lagendijk has been Member of the European Parliament from 1999 to 2009. He is now living and working in Turkey as a columnist for the Turkish dailies Zaman and Today's Zaman.

Originally published on todayszaman.com.