Nato and Russia held their first direct talks in two years on April 20, which while aimed at easing tensions and addressing key mutual security issues appeared to only harden the confrontational atmosphere.

"Nato and Russia have profound and persistent disagreements. Today's meeting did not change that," Nato Secretary General Jens Stoltenberg said after the session in Brussels of the Nato-Russia Council, a body set up in 2002 to help cooperation but suspended in April 2014 after Russia's seizure of Crimea.

"Nato allies remain firm that there can be no return to practical co-operation until Russia returns to the respect of international law. But we will keep channels of communication open," Stoltenberg said.

"All 29 members of the Nato-Russia Council agreed today on the need for a full and rapid implementation of the Minsk agreements [on Ukraine]," he added on a positive note. However, all actors and peace settlement sponsors in the conflict that erupted East Ukraine in mid-2014 say their opposites are failing to do their bit to fulfil agreements reached last year in the Belarusian capital.

Meanwhile, representatives of the Kremlin, which has long regarded the military alliance as encroaching on its borders from multiple sides, went into the talks amid what spokesman Dmitry Peskov described as a "total lack of trust".

Reportedly initiated by Nato, the meeting of envoys of the 28 alliance members and Russia covered efforts to end the separatist conflict in East Ukraine, the need to support Afghan security forces fighting the Taliban, and steps to avert such potentially disastrous military incidents as occurred in the Baltic region on April 12.

After a Sukhoi Su-24 attack jet flew within 10 metres of the destroyer USS Donald Cook, US Secretary of State John Kerry slammed the Russian actions as "reckless and provocative". Furthermore, "under the rules of engagement that could have been a shoot-down", Kerry noted.

Stoltenberg also called the aerial stunts "unprofessional and unsafe" and said they "underline the importance of open military lines of communication, predictability and risk reduction". More inflammatory from the Kremlin perspective were remarks by his deputy Alexander Vershbow, who said "pressure on Russia should be continued" and that Nato will help Ukraine strengthen its defence capability.

Upping the ante further before the Brussels meeting, Polish Foreign Minister Witold Waszczykowski branded Moscow a greater threat than the Islamic State terrorist movement. In turn, Russian officials cited perceived arrogance and "zealous Russophobia" among Nato members.

Baltic flashpoint

Moscow has for years opposed Nato's enlargement to include former Warsaw Pact members and the establishment of bases in some former Soviet republics. The Baltic region in particular is tenser than at any time since the Cold War, prompting Latvia to build a wall on its border with Russia, and Lithuania to reintroduce conscription.

Concerns were compounded by a report in February by Rand Corporation that concluded that Nato forces in Estonia, Latvia and Lithuania would be overrun by a Russian invasion in under three days.

"As currently postured, Nato cannot successfully defend the territory of its most exposed members," the report said after a simulated invasion scenario. Nato has since increased its presence in the Baltics, drawing fresh Russian protests about encroachment.

US Secretary of Defense Ash Carter said then that the US was more worried about Russian actions than at any time since the collapse of the Soviet Union, and the US government announced that it would quadruple military spending in Europe.

Russian Foreign Minister Sergei Lavrov recently emphasised that Moscow will not allow Nato to entangle it in confrontation.

"We have seen an unprecedented military build-up since the end of the Cold War and the presence of Nato on the so-called eastern flank of the alliance with the goal of exerting military and political pressure on Russia for containing it," Lavrov said during a talk at the Mongolian Foreign Ministry in Ulaanbaatar on April 14.

With an accompanying "propaganda campaign to demonise Russia", Nato is "busy searching for an enemy to assign a meaning to its further existence", TASS quoted Lavrov as saying. But "Russia does not plan and will not be drawn into a senseless confrontation", he added.