Dutch soldiers are to spend the next six months defending the skies over eastern Poland in what one officer has called “the grey zone between war and peace”.

The 300 troops will take control of the Patriot missile defence system from Germany, which has been responsible for responding to potential Russian attacks for the last year.

Former commander of the Dutch armed forces, Mart de Kruif, said they would be monitoring the skies “24 hours a day, seven days a week” for ballistic missiles, drones and other objects.

“We have seen Nato airspace being infiltrated from the east, often by what we presume to be Russian drones,” De Kruif said. “Nato said at the time: this is the limit. We are going to intensify our air defences.”

In September Dutch F-35 fighter jets were involved in shooting down Russian drones that crossed the Polish border during a major aerial attack on Ukraine.

Eastern Poland is where Nato stores military hardware that its members have donated to Ukraine and co-ordinates the transport across the border.

The Germans did not have cause to engage the Patriots in the last year, but De Kruif said they had “undoubtedly seen a lot of things on their radar”.

The deployment of the 300 Dutch troops from De Peel airbase in Limburg is beginning this week, with the aim of having the unit fully operational by mid-December.

Lieutenant Colonel Wesley told the Defensiekrant, the ministry of defence’s in-house newspaper: “It feels like everything is fine in the Netherlands and the rest of Europe. We’re all just getting on with our lives.

“But at the same time we’re in a grey zone between war and peace. We need to be alert.”