Donald Trump on IS: How important is surprise in Mosul? Jonathan Marcus

Diplomatic correspondent

@Diplo1on Twitter Published duration 11 October 2016

image copyright Getty Images image caption Does Donald Trump have a point in criticising the fact plans to recapture Mosul are being projected?

"How stupid is our country?" asked the Republican presidential contender Donald Trump in this week's presidential debate.

He was referring to the fact that US commanders have telegraphed the impending attack on the so-called Islamic State's stronghold of Mosul which is due - so we are told - in a matter of days.

Leaving aside that so much of formerly IS-controlled territory has been recaptured, and that Mosul is self-evidently the last major centre in the Iraqi government and the coalition's sights, does Mr Trump have a point? How important is the element of surprise in military operations?

Total surprise is rare in military operations - the unexpected hammer blow that comes from out of the blue.

The Japanese attack on the US naval base at Pearl Harbor on the morning of 7 December 1941 was just such an occurrence. The last-ditch Nazi offensive in the Ardennes in December 1944 - what's become known as the "Battle of the Bulge" - also took the Americans totally by surprise in a poorly defended sector of the front.

But more often surprise is operational or tactical rather than strategic. The Germans knew full well that the Allied landings on the shores of France in 1944 - D-Day - were coming. The problem is that they did not know exactly where or when. Elaborate operations were conducted to try to fool the Germans into thinking not just that the attack would be elsewhere, rather than in Normandy, but also that once it was under way, that the main thrust would be elsewhere, encouraging the Germans to hold back essential reserve forces for vital days while a beach-head was established.

Division and discord

The battle for Mosul is hardly going to be on the epic scale of D-Day. Having already lost much of the territory it controls, IS commanders in the city know that they are next.

image copyright AFP image caption The lack of surprise may be working in coalition forces' favour, some argue

So making it clear that Mosul is the next target - and, to be fair, the preliminary operations for the offensive have been under way for some months - is hardly giving away a state secret, despite Mr Trump's concerns.

Indeed, according to Brigadier Ben Barry, senior fellow for land warfare at the International Institute for Strategic Studies in London, telegraphing one's intentions, when there is already no real shroud of secrecy, can yield several advantages.

"It may encourage some IS fighters to withdraw from Mosul - indeed some are already leaving - and once mobile they become targets for coalition air power," he said. Some civilians may also be encouraged to flee, potentially reducing their casualties in any subsequent battle.

The propaganda signals of an impending hammer blow have also served, according to Brig Barry, "to sow divisions and discord in the IS ranks".

"There are clear signs", he told me, that "IS's conventional fighting capability has reduced and that the organisation is under pressure with cuts to salaries, reduced training for new recruits, and the organisation's internet campaigns showing some strain."

If strategic surprise is impossible, then tactical surprise may still be achieved. It is noteworthy that little or nothing is being said about the mechanics of how Mosul will be recaptured. Brig Barry cites the attack on Taliban positions in Marjah, Afghanistan - so-called Operation Moshtarak - in 2010.

The operation was telegraphed in advance to try to achieve many of the goals set out above. Strategic surprise was impossible but tactical surprise was achieved, for example, by many of the attacking forces being inserted close up to Taliban positions by helicopter. He is not suggesting a similar heli-borne assault on Mosul, just highlighting that all sorts of opportunities are available to Iraqi commanders once the city itself is surrounded.

image copyright EPA image caption Sometimes letting the enemy know you are coming works in your favour

Military matters cannot be an open book and secrecy is indeed important. However Mr Trump's claims that surprise has been stupidly given up bears little scrutiny. Mr Trump certainly plays his own strategic cards close to his chest. His policy towards stifling IS is a secret known only to himself.

Others might call it a mystery, since in broad strategic terms, the tools available to any US administration are broadly the same. It is their combination and the success with which they are applied that determine the outcome.