A hovercraft performs a demonstration in Albert dock outside the ExCel centre on September 13, 2011 in London, England. The Defence and Security Exhibition on September 13, 2011 in London, England. ExCeL London is hosting the exhibition with hundreds of manufacturers from all over the world displaying their hardware. (Photo by Dan Kitwood/Getty Images)

A sailor walks on the deck of a Skjold class missile fast patrol of the Royal Norwegian Navy at anchor next to the ExCeL exhibition centre on September 12, 2011 in London, England. ExCeL London is hosting the Defence and Security Exhibition 2011. Exhibits include an F16 fighter and naval vessels. (Photo by Peter Macdiarmid/Getty Images)

Naval vessels are moored alongside the ExCeL exhibition centre on September 12, 2011 in London, England. (Photo by Peter Macdiarmid/Getty Images)

A speedboat performs a demonstration in Albert dock outside the ExCel centre on September 13, 2011 in London, England. (Photo by Dan Kitwood/Getty Images)

Visitors look at a BAE Systems RG41 combat vehicle on display at the Defence and Security Exhibition on September 13, 2011 in London, England. (Photo by Peter Macdiarmid/Getty Images)

A soldier sits in an air cooled bomb disposal uniform at the Defence and Security Exhibition on September 13, 2011 in London, England. (Photo by Peter Macdiarmid/Getty Images)

Uniforms and weapons are displayed at the Defence and Security Exhibition on September 13, 2011 in London, England. (Photo by Peter Macdiarmid/Getty Images)

Members of Oman's military look at weapons at The Defence and Security Exhibition on September 13, 2011 in London, England. (Photo by Peter Macdiarmid/Getty Images)

A visitor walks past the Turkish missile manufacturer Roketsan's stand at the Defence and Security Exhibition on September 13, 2011 in London, England. (Photo by Peter Macdiarmid/Getty Images)

A soldier displays new technology at The Defence and Security Exhibition on September 13, 2011 in London, England. (Photo by Peter Macdiarmid/Getty Images)

Gas cannisters and “explosive grenades” are displayed at the Defence and Security Exhibition on September 13, 2011 in London, England. (Photo by Peter Macdiarmid/Getty Images)

A French military combat command vehicle is displayed at The Defence and Security Exhibition on September 13, 2011 in London, England. (Photo by Peter Macdiarmid/Getty Images)

Visitors look at a General Dynamics Scout Special Vehicle on display at the Defence and Security Exhibition on September 13, 2011 in London, England. (Photo by Peter Macdiarmid/Getty Images)

A visitor tries out a Heckler and Koch assault rifle at the Defence and Security Exhibition on September 13, 2011 in London, England. (Photo by Peter Macdiarmid/Getty Images)

South African body armour is displayed at the Defence and Security Exhibition on September 13, 2011 in London, England. (Photo by Peter Macdiarmid/Getty Images)

A French soldier stands near a military combat command vehicle on display at The Defence and Security Exhibition on September 13, 2011 in London, England. (Photo by Peter Macdiarmid/Getty Images)

A small demonstration takes place outside the ExCel centre during the Defence and Security exhibition on September 13, 2011 in London, England. (Photo by Dan Kitwood/Getty Images)