By Mick Krever, CNN

In an interview with CNN's Christiane Amanpour on Tuesday, Estonian President Toomas Hendrik Ilves called for a "physical presence on the ground" in the region as a deterrence against Russia.

Estonia, a former Soviet republic that shares a border with Russia, is now a member of NATO. Its leadership has been outspoken expressing concern about Russia's incursion into Ukraine.

"We need more exercises," President Ilves said. "We think that the decision to increase the number of planes providing air policing in the region is a very good one."

"But given the uncertainty that we see to the east and the kinds of actions that we’ve seen in the east, we need to make sure that others understand that this is not something to play around with."

Estonia's plea on Russia Click to watch video

Amanpour asked President Ilves what he thought Russian President Vladimir Putin's "goal" was.

"We are in new territory right now. The rules have been broken."

Russia's interference in Ukraine and annexation of territory are "out of a playbook that we last saw before World War Two," the president said.

Putin's playbook from 'pre-WWII' Click to watch video

"So that makes it very difficult for us to actually be able to guess what is in one or another person’s mind."

Estonia has had more experience with Russia than most. President Putin was instrumental in trying to organize a referendum on autonomy for some of the Russia-speaking areas of Estonia, which was then struck down.

“The propaganda that is emanating from the Kremlin in the case of either Ukraine or the Baltic countries – or, in fact, the United States – is at a level which we have not really since seen since the 1950s,” President Ilves said.

The question for those countries is how they can rein in President Putin. Two rounds of sanctions targeting Russian and former Ukrainian leaders seem to thus far have had little effect on changing Putin’s thinking.

“I think the consequences of his actions will lead to a dramatic downturn that we already are beginning to see in the economy of Russia,” Ilves said.

The European Union will likely, the president said, extend the list of “sanctions and sanctioned individuals” at its next meeting of heads of state.

“Is that enough,” Amanpour asked, “to deter President Putin?”

“We don't know,” President Ilves said. “Now that's our problem.”

Putin's actions 'defy understanding' Click to watch video

President Putin’s actions are not in the “understanding we have of the behavior of countries, as we've developed those understandings over the last quarter century.”

“It's hard to predict, frankly.”

“But long as we think that the…rules of behavior are more or less understandable, then you would think that sanctions of this type will have an effect.”