British troops are to be deployed to the Baltics as part of a long-term Nato mission to deter Russian aggression.
Defence Secretary Michael Fallon said a "small number" of soldiers would be stationed there to "watch over our allies on the eastern borders".
RAF Typhoon fighters are already in the region as part of the Baltic Air Policing detachment and have been called into action in recent months.
Russia's President Vladimir Putin has said the only way to deal with terrorists in Syria is 'to act preemptively'.
Speaking at a government meeting today Putin said he would not sit and wait for terrorists to succeed in Syria and then come to Russia, before suggesting international efforts needed to be combined to stop the problem spreading.
The comments came as it was revealed Russia had carried out its first air strikes in Syria.
Incursions by Russian jets into Turkish airspace have prompted a stern response from Nato's most powerful ally.
Here's what you need to know about this latest development in the increasingly bloody, complicated and volatile conflict.
Russia urges world leaders to unite to fight terrorism in Syria amid criticism that air strikes have targetted rebel fighters and civilians.