The recent failure of undersea cables serving the Middle East and North Africa highlights the vulnerability of submarine communications to terrorist and other deliberate attacks.

Matt Walker, a senior analyst at Ovum, warned that risks from sabotage must be considered as the economic importance of the world's undersea communications infrastructure grows.

The recent spate of incidents shows that, despite multiple layers of built-in reliability, the infrastructure is "highly vulnerable".

"There is an unspoken assumption that the networks are safe from deliberate human sabotage. The recent cable failures in a politically volatile region has called this assumption into question," said Walker.

"If ports, railways, gas pipelines and other networks are being secured against possible sabotage, we must similarly increase the security of undersea optical highways.

"Guaranteeing reliability is impossible, but an improvement on the current hands-off approach is long overdue."

The analyst warned that the economic cost of losing, or even just slowing down, international communications is extremely high.

"This risk has to be factored into the calculations behind the investment level and design of undersea optical networks," he concluded.