While some have returned and others promised to do so, ongoing concerns about security have forced a sense of caution among many.

FORBES: Protest Pains Could Hinder Libyan Energy Recovery

The NPT offered non-nuclear weapon states all the know-how and most of the materials they needed to become nuclear armed, if only they promised not to do so.

CENTERFORSECURITYPOLICY: Dangerous disarmers

But they promised not to do so by issuing new shares, which erodes the value of existing investors' shares.

WSJ: Deutsche Bank Plans Capital Boost

But even if large numbers of Sunnis wish to vote in the promised referendum, they may well not feel safe enough to do so.

ECONOMIST: Iraq's constitution

NATO, it had promised to guard the villagers and was preparing to do so.

ECONOMIST: Kosovo

What we try to do is manage our schedules to ensure that we are delivering what we promised, and I think that having done so consistently has led to a high degree of client retention.

FORBES: Intermarine Executives Discuss Ship Financing, Piracy, and Global Maritime Trade

New GFA chairman Dr Nyaho Tamakloe has promised to prevent football cases from being settled in court by banning any the clubs who do so.

BBC: Ghana suspends league

The company said messages would be encrypted when transmitted and it promised not to analyse or provide third-party access to the contents unless required to do so by the courts.

BBC: Telefonica unveils data-based communication app Tu Me

It has told countries that promised to hand dirty power plants all the permits they needed for years to come that they could not do so, because such pledges might undermine any chance of introducing a tougher regime after 2012.

ECONOMIST: Europe's emissions-trading scheme

While Baidu has promised to more clearly differentiate organic and paid search results for a long time, it has still failed to do so.

FORBES: Has China's Internet Become Inhospitable To Startups?