By Neil Connery: ITV News Correspondent
Tense relations with Russia over Ukraine have forced Nato to look again at its capabilities and military assets in the wider region - with two RAF jets called on only yesterday to investigate a Russian spy plane in international airspace.
ITV News has been given special access by Nato to its current exercise underway in Estonia, codenamed Steadfast Javelin 1.
More than 6,000 troops from nine Nato countries - including the UK - are involved.
Yesterday, two RAF typhoons involved in the ongoing exercises were called on to investigate an unidentified aircraft.
The plane was a Russian Ilyushin 18 reconnaissance jet.
With tensions high in the region there have been around 100 similar incidents so far this year.
Last week two Danish F-16s along with two RAF Typhoons were ordered to intercept a Russian military helicopter over the Baltic Sea.
The Russian Ka-27 helix had taken off from a warship but refused to identify itself as it skirted Latvian airspace. The helicopter headed back to its combat ship by the time the Nato jets arrived.
Nato is determined to send a clear message that the Baltic States will be defended and the alliance means business when it comes to collective security of its members.
The Baltic states, which joined Nato 10 years ago, do not have fighter jets of their own.
The task of policing Baltic airspace is shared by four RAF Typhoons and four Polish Air Force Mig-29s based in Lithuania, four French Rafale jets in Poland and four Danish F-16s in Estonia.
The Commander of the Estonian Air Force Colonel Jaak Tarien says running these exercises is "is the best guarantor of peace" in the region.
"These are difficult political times and this is the best way to avoid mistakes and misjudgements by others," he said.