The Prince of Wales is showing support for UK troops guarding Natos border with Russia, with a two-day visit to Estonia.
Prince William will see soldiers training in the Baltic state as part of a multinational force intended to deter Russian aggression on Natos eastern flank.
The visit begins on Thursday morning with a meeting with Estonias President, Alar Karis, in Tallinn, followed by a visit to a school teaching refugees from the war in Ukraine.
There are about 900 UK troops deployed to Estonia, including soldiers from the Mercian Regiment, of which Prince William is colonel-in-chief.
The visit comes amid uncertainty over the war in Ukraine and worries about Russias next steps.
Earlier this week, Estonia was one of the countries on Russias borders to withdraw from a treaty banning anti-personnel landmines - a sign of rising tensions.
Its navy has been trying to prevent sabotage of undersea cables.
And the country is planning to increase military spending to 5% of its gross domestic product (GDP).
Prince Williams visit to this small, high-tech country is another moment of royal soft power, sending a message about the UKs commitment to defending the Baltic states.
It follows a visit a few months ago by UK Prime Minister Sir Keir Starmer.
And talking to students and staff at the University of Tallinn, the royal visit seems to be warmly welcomed.
It is seen as a sign of support from Western allies for a country, with a population of only 1.3 million, keenly aware of its need for military assistance.
The threat from Russia seems very real from their perspective.
"Were more or less preparing for war," Catlyn Kirna, a senior lecturer specialising in cyber-security, says.
There is already a constant wave of cyber-attacks and misinformation from Russia, which will keep "testing the water" to see how Nato responds.
And as a former part of the Soviet empire, Estonia looks at the current situation in Ukraine with growing concern.
"If Ukraine falls, we will have to fight for our lives," Catlyn says.
And with an 18-year-old son, it feels like a very personal worry.
The view from Eastern Europe, on Natos front line, gives a much sharper perspective on issues around Russian expansionism, Catlyn says.
"In western Europe, it might be bad news," she says.
"For us, its the end of the world."
Political-science student Julija Raudkivi says: "[US] President Trumps comments and behaviour created anxiety for many Estonians.
"We talk about it a lot," she says, concerned by Trumps apparent lack of enthusiasm for the Nato alliance.
"Theres definitely some underlying anxiety about the threat posed by Russia.
"Its the proximity, were so close."
Julija backs the push for more spending on arms and the strengthening of Nato forces.
Since Russias attack on Ukraine, she says: "It makes you feel like war is just behind the door."
Liberal-arts student Sharon Kaasik says young people have grown up hearing stories about the Soviet regime before Estonias independence in 1991 and there are worries about the past returning.
But she trusts in the military alliances and wants European countries to work more closely together.
Arts and music student Sander Poldmaa, 21, wants to defend his country and volunteers in Estonias defence forces.
"Were a small country and Russia is right beside us," he says.
And he is unsettled by Trumps "childish" behaviour.
Sander wants Nato to be stronger but says it is about deterrence.
"The main point for me is that I dont want the war to happen," he says.
"But we need the ability to defend ourselves.
"The horror of people in the front line in Ukraine, I wouldnt want that for anyone."
Estonia has given more aid to Ukraine, as a proportion of GDP, than any other country, four times as much in relative terms as the UK.
In the cold winter sunshine in Tallinn, it is a reflection of how close the threat feels.