These days, we only call it propaganda when despotic North Korean leaders visit their troops.

But whether used as a force for good or bad, military propaganda is still a modern political tool.

Some of the most striking images of leaders come when on a war footing.

Margaret Thatcher, Boadicea-like, astride a tank in West Germany in 1986.

President George W. Bush holding up a Thanksgiving turkey for troops in Baghdad. Tears tracking down his face at a ceremony to honour a Marine, blown up on patrol in Iraq.

Tony Blair in Macedonia on the phone to British troops on the Kosovo border.

This week it was John Key’s turn to walk the ground of deployed operations. He swooped into Camp Taji to spend a few hours with more than 100 Kiwi soldiers who are training the Iraqi army.

It would be deeply unfair to suggest Key’s motives were anything but genuine. Sending sons, daughters, mothers and fathers into war is the most difficult, and lonely, decision any leader can make.

But the political spin machine never stops turning. And it is a well-established rule of politics that when a Government sends soldiers into a battle zone, the unpalatable decision must be sold, and resold, to the public.

That’s why these visits rarely take place without a travelling media pack.

Many are still wary of the deployment and Key had to work hard last year to soft-soap the public, agnostic after the War on Terror.

A February ONE News Colmar Brunton poll put support at 48 per cent. Another, taken in April, showed almost half of respondents believed maintaining good relations with US and UK allies was the main reason for participation.

Since New Zealand joined the anti-Islamic State effort, the international coalition has made few gains.

Extremists still hold large chunks of northern and west Iraq. Tumbling oil prices and decades of war sent the country broke – and the army is under-resourced.

The US-led coalition believes local fighters lie at the heart of retaking the Anbar region – that was dealt another blow this week when 70 from a pro-Government Sunni tribe were slaughtered near Ramadi.

The Baghdad Government recently made clear they believe ISIS will only be degraded with more international air-strikes.

At the same time, Western powers are on the back-foot in Syria. While they power-struggle with Russia, ISIS's reign of terror spreads.

And so, this exercise was as much about focusing on the ‘good bits’ of this war (Kiwi experts drilling Iraqi recruits in the fight against ISIS) as Key making good on his promise to call on troops.

It reminds voters back home - bombarded daily with TV coverage of the ‘bad bits’ (ISIS’s horrifying creep and the West’s failures) - of the claimed purpose of Kiwi intervention.

On these trips politicians and the media both tread a fine line. Journalists are complicit in a pre-cooked photo-op. This is uncomfortable but entirely necessary.

Soldiers, their guns and helicopters become a prop for flak-jacketed politicians in their PR war. The images must be powerful enough for audiences back home, but without the pilgrimage appearing cynical or opportunistic.

Did Key’s Iraq visit succeed? Those intractably opposed to the mission will likely judge no, viewing it as a contrived stunt.

Supporters will see it as a show of Key’s resolution that this was the right course of action.