The annual Nato summit in Warsaw came to an end on July 9 with a some tough talk on Russia and both sides moving to build up military forces along their borders.

As well as basing more forces in Poland, Nato said it will permanently station 3,000 troops in the three Baltic states as a "tripwire" strategy. If Russia were to invade Estonia, Latvia or Lithuania, these would be the first forces to engage, with the automatic triggering of Nato's Article Five to commit the rest of alliance to war with Russia. Baltic state leaders welcomed the move to beef up Nato's eastern periphery.

"This is a breakthrough that unambiguously demonstrates Nato's solidarity and the fact that Estonia is better protected today than ever before," Estonian Prime Minister Taavi Roivas said in Warsaw. "[Stationing of troops] is a direct confirmation of the Alliance's defence and deterrence posture – a signal that an attack on one is an attack on all and it’s not worth picking a fight with us."

Before the summit opened on July 8, Nato Secretary-General Jens Stoltenberg said it came at a "critical time" for the alliance as it faced a "more assertive Russia, intimidating its neighbours, and changing borders by force", as well as violence in North Africa and the Middle East and terrorism, cyberattacks and ballistic missile proliferation.

Nato is responding by "implementing the biggest reinforcement of our collective defense since the end of the Cold War", Stoltenberg said in a climate of growing brinkmanship between the alliance and Russia. Russia in May already responded to Nato activity in the Baltic region by announcing the deployment of 30,000 more troops its western and southern flanks.

Although Russia did not participate in the summit in Poland, its spectre loomed large over the proceedings. After the event, the Foreign Ministry in Moscow denounced Western "attempts to demonise Russia" and Nato's focusing of efforts on "containment of a non-existent threat from the East".

"We expect from Nato representatives explanations regarding the organisation's 'reinforcement in all directions' during the upcoming Russia-Nato Council meeting at the level of permanent representatives due on July 13," TASS quoted ministry spokesperson Maria Zakharova as saying on July 10.

Added Russia's ambassador to Nato, Alexander Grushko: "Nato took certain decisions to strengthen [its] eastern flank and Nato should realise that there will be also military consequences." It is "absolutely clear that what Nato is doing on [its] eastern flank is against Russia", Grushko told the BBC.

The defiant stance of both sides reflects rising tensions in recent months, with a Nato warship and a Russian jet passing only a few metres apart in the Baltic Sea in April. Moscow also termed US missile defences activated in Romania in May a direct threat to Russia's international security and stability.

For its part, Nato's leadership became particularly hawkish. While US President Barack Obama has tried to rein the organisation in, leaked emails from the former supreme commander of Nato forces in Europe, General Phillip Breedlove, showed he lied about the extent of the Russian military build-up on the border of Ukraine in 2014, released fake photos and generally lobbied the US government for a more aggressive stance in Ukraine's eastern region, including supplying the Ukrainian army with "lethal assistance" and materiel.

Nato issued over 20 warnings of an imminent invasion of Ukraine by Russia, according to reports in 2014 and 2015, in part to "leverage, cajole, convince or coerce the US to react" to Russia, according to the emails. Breedlove quit as Nato commander in May and has since retired, but Nato remains seriously concerned by Russia's obvious aggression in Ukraine's Donbas and the annexation of the Crimea in 2014.

Meanwhile, Nato's leaders have pledged to bolster Europe's defences in the face of what they called an "arc of insecurity and instability" from Moscow to North Africa.

"In the nearly 70 years of Nato, perhaps never have we faced such a range of challenges all at once: security, humanitarian, political," Obama told reporters on July 9 at the Warsaw summit's close. "In this challenging moment I want to take this opportunity to state clearly what will never change: the unwavering commitment of the United States to the security and defence of Europe."

Obama went on to say there will be no return to "business as usual" with Russia until it withdraws its personal from eastern Ukraine and returns the Crimea to Kyiv. He stood with Ukraine's President Petro Poroshenko and promised Washington's continued support in its stand-off with Russia.

The Nato summit delegates roundly placed the blame for the lack of progress in implementing the Minsk II peace deal at Moscow's feet. Ahead of the meetings, German Chancellor Angela Merkel met with Obama to discuss Ukraine and said they agreed to discuss how to advance the political process and improve security in Ukraine. "There's no cease-fire in Ukraine," Merkel said. "But that is the precondition for local elections to take place and the political process to go forward."

Russia has blamed Kyiv for the lack of progress on Minsk II, pointing out that Poroshenko has failed to deliver on three of main requirements by the deadline of 2015: to change the constitution, hold regional elections, and sign an amnesty law for participants in the fighting.

With Ukraine now effectively a frozen conflict, tensions are continuing to rise between Russia and Nato. While politicians search for a diplomatic solution, Russia in particular is continuing to build a serious military force in its western regions as is default strategy.

On July 8, the day the summit opened, Russian President Vladimir Putin signed a decree fixing the minimum number of servicemen at 1mn, with another 885,000 people in the employ of the Ministry of Defence. The new statutory limit accords Russia the largest armed forces since the fall of the Soviet Union, with a quarter of million more men under arms than at the low point in the 1990s.

This month's decree caps a series of reforms to Russia's standing army that Putin began in 2008. The 1mn servicemen include 300,000 non-commissioned soldiers performing national service and another 352,000 kontraktniki, or professional personnel serving on paid contracts. In addition, there are 250,000 officers and 31,000 volunteers, totalling just under 1mn, according to Russian Defence Policy.