BRUSSELS — The Ukraine crisis and Russia’s aggressive behavior have hit NATO right between the eyes.

Utterly caught off guard, the defense alliance has begun asking itself how it must react, both in the short-term actions, as well as bigger questions about NATO's role for the future.

The pressure to be decisive has a firm deadline of September, when a key summit will be held in Wales of NATO country heads of state and government. The alliance, however, is deeply divided and no country is seriously prepared to spend much more money on higher readiness for action and modern equipment.

But it’s becoming clear that it's going to come to that. And the NATO foreign ministers who gathered this week for talks in Brussels know it too. In view of the threat from Russia, they are working on a new Euro-Atlantic oath of allegiance that is due to be approved at the NATO summit.

One particularly interesting fact with regard to this oath is that the plan for the future of the trans-Atlantic alliance also contains the obligation that Europeans increase their defense spending. That’s a sensitive topic, especially for Berlin. Three weeks ago Defense Minister Ursula von der Leyen explained that spending would not be shored up, and pointed out that the German defense budget is 32 billion euros. But that’s not enough for the Americans. They finance more than 70% of NATO’s budget, and Washington wants stronger commitment from other rich member countries like Germany.

That’s also going to be necessary because in view of the new threat from the East, NATO wants to increase readiness with better equipment, more maneuvers, training and reaction capacity for troops — that’s the strategy for the future. What that means specifically for Eastern Europe and the Baltic states is still unclear.

Philip Mark Breedlove, Supreme Allied Commander Europe of NATO Allied Command Operations, intends to present some first concrete plans on June 30. The American Air Force General is caught in the middle of the contrasting views dividing NATO members. The Baltic and Eastern European countries, particularly Poland, want adequate protection from Russia.

Boots on the ground

Estonia's Foreign Minister Urmas Paet told Die Welt that the Baltic nation has a clear idea what is needed on security. "Estonia believes it necessary for NATO ground troops to be permanently stationed on its territory for as long as security in Europe is unstable," he said.

Collective defense readiness and solidarity among NATO partners was of "fundamental importance," Paet went on to say. However Germany, France and southern European countries want to avoid Russian provocation and are against the permanent stationing of troops in eastern Europe. Washington is cautious on this score as well.

NATO diplomats have reported that, in opposition to the wishes of the eastern NATO states, "no permanent stationing of NATO forces is foreseen in Eastern Europe." Instead, in the future, longer and more substantial maneuvers as well as regular multinational training exercises with rotating participation would take place in the East. Reconnaissance by planes and ships would also be improved.

NATO is particularly alarmed by Russia’s newly-developed "subversion strategy," which it refers to internally as "hybrid war." According to NATO analysts, Moscow’s new military tactic is to infiltrate specific areas with military experts — called "little green men" in NATO jargon — that advise, incite and train rebels such as those in eastern Ukraine in the use of military equipment.

"They destabilize without firing a single shot," a senior NATO officer said. This infiltration strategy is, according to NATO experts, supported by conventional Russian forces gathered along Ukrainian borders. The troops vary in number, are flexible, can assemble quickly at set points, and are able to go from training to attack mode immediately.

NATO is working feverishly on finding an answer to the new Russian double military strategy. One reaction would be to invest in the NATO Response Force (NRF) and make it better equipped for action with quicker reaction times. NATO has recognized that it has to react to the Russian threat with units that can be moved quickly.

"We have to be in the position to get the right troops to the right place quickly," said one military strategist.

But turn it this way or that: Russian aggression is a very real test of NATO capacity. The challenge is that it must find the "right" strategy and invest in the alliance’s defense preparedness even at a moment when member budgets are growing ever tighter.