I've been out and about in Barrhead over the past few days and there has been real revulsion at the brutal murder of Drummer Lee Rigby - a young hero whose life was stolen. The barbaric act of terror, so graphic on our TV screens, will not go unpunished and nor will it be forgotten. The family of that young, distinguished slain soldier will be in the thoughts of everyone who has a heart and in the prayers of each of us who has a faith.

So how should we respond? Politicians shouldn't change our foreign or defence policies. A tiny minority in our country who will act out a malevolent revenge which the police will deal with. But for everyone else we have a different responsibility. Our reaction is one of the things that the extremists hate about us. It is that British spirit of resolve, solidarity, openness and justice that should triumph.

Our nation is a remarkable blend of modernity and enduring institutions including the Monarchy, NHS and the BBC. But nothing captures that spirit more exquisitely than our Armed Forces. People from every corner of our islands, all with their own histories, many placing a personal faith in their own God. I remember a visit to Afghanistan when I met some of the many hundreds of British Muslims, patriots one and all, each serving in Her Majesty's Forces.

We all have it in us to celebrate their quiet dignity.

We can give to one of our great military charities by all means but lets do something else as well. Armed Forces Day on June 29 is a chance to demonstrate the strength of unity between the Services and our country.

I was troubled at suggestions that members of the Armed Forces should not wear their uniforms in public in response to Wednesday's atrocity. In the chaotic aftermath this may have been momentarily necessary, but a longer-term shift towards our Forces and veterans being invisible on British streets would be the wrong response.

David Cameron's advice after Wednesday was to 'act normally'. I agree. Up to a point. Everyday life must continue, but a haunting act demands an extraordinary reaction.

That is why the forthcoming Armed Forces Day can mark a moment of defiance and celebration: defiance against our aggressors, celebration of who our Armed Forces are and what they achieve.

As long as the security advice is clear then on June 29 members of Her Majesty's Armed Forces could be encouraged to publicly wear their uniform even if off-duty. Veterans of all generations could wear their medals or military attire. And we, all of us can do something important that will take only three seconds. Because that's all it would take to say 'thank you' to a member of our Armed Forces.

We don't just want to see uniformed personnel in ceremonial parades; we want to see them in our streets and shops, fairs and fetes, on public transport and as part of our communities. We all know that during the 1970s and 1980s Forces were advised not to wear uniforms off-base because of IRA/INLA terrorism. That was relaxed after the Belfast Agreement.

It is less than a week since the horror in Woolwich and just over a month until Armed Forces Day. But we should all ask ourselves: "What am I personally going to do in memory of all of those who have been lost including Lee Rigby or injured or who still serve today?" "This year don't leave it to someone else to celebrate Armed Forces Day.