PARIS — What can Europe do after Kiev's desperate call for help in dealing with the invasion of Russian troops in eastern Ukraine, where separatists are gaining control? Let's leave aside for the moment the hypothesis of military aid. European defense doesn't exist. What's more, we run the risk of escalation — an imbalance that no one in the West seems disposed to take, given that Ukraine is not part of NATO.

So it's not possible for Ukrainian President Petro Poroshenko to refer to Article 5 of the North Atlantic Treaty and benefit from automatic military help from NATO partners in the event of invasion. Certainly, NATO recently intensified its partnership with Kiev because "a sovereign, independent and stable Ukraine is essential for Euro-Atlantic security."

But it's impossible to go beyond intensifying military exercises or air patrols along Ukrainian borders, like those that yielded the satellite images revealing the presence of 1,000 Russian soldiers apparently directly involved in the fighting in eastern Ukraine.

On the eve of today's special meeting of NATO ambassadors in Brussels, General Philip Breedlove, Supreme Allied Commander Europe of NATO Allied Command Operations, reaffirmed that the organization would "respond militarily" to any similar incursion onto the territory of NATO members. That didn't do much to reassure Ukrainians who aren't members of the "club."

Tightening EU sanctions against Russia would be an easier reaction, but would it be more effective? The two first European salvos have weakened the Russian economy considerably, with growth and exports lowered, devaluation of the ruble, a tumbling stock market, and freezes on visas and the assets of oligarchs in foreign banks.

But none of this has weakened Vladimir Putin's determination. By way of reprisal, the Russian president placed an embargo on Western agricultural exports. Yet Brussels seems resolved to put extra pressure on. The future High Representative for Foreign Affairs who will replace Catherine Ashton at the end of this week will have to contend with the reticence of countries that import Russian gas or oil (which makes up 30% of German consumption, for example). There is also a shared fear of aggravating the recession in the euro zone.

"The best way for the EU to answer Kiev's cry for help? Strengthen economic aid," one French diplomat concludes. Riddled with debt (the gas deficit alone amounts to $4.6 billion) and faced with an economy threatening to collapse unless an estimated $66 billion comes its way, Ukraine desperately needs EU benefits outlined in the framework of the EU-Ukraine Association Agreement signed last June. 

Consolidation of this agreement, decided in Minsk, could pave the way to a series of cooperative efforts that would make it possible for the country to finance indispensable reforms. Together with the "Merkel plan" ($659 million to reconstruct the Donbas war zones), this agreement is the real measure of what Europe can do right now in the framework of its eastern partnership: credits, financial and technical cooperation, and opening up to Ukrainian products. But most certainly: no arms and no military aid.