Even as a tentative, three-day ceasefire in Gaza was beginning yesterday, the Foreign Office minister Baroness Warsi finally lost her patience with the UK's policy on the region and resigned from the Government.

In a letter to the Prime Minister, she said the UK's policy on the conflict was inconsistent with British values and support for international justice; it was, in short, morally indefensible and she could no longer be part of the government.

The resignation should probably come as no surprise because not only has Baroness Warsi's anger been simmering on the issue for a few days, her differences with David Cameron have also been clear. Mr Cameron has consistently said Israel has the right to defend itself; Baroness Warsi, on the other hand, has said there can be no justification for the deaths of children.

The baroness may be unlikely to achieve a change in policy with her resignation, but she is right to be concerned about how Mr Cameron and his Government have handled Gaza. Mr Cameron has said many of the right things in theory, but it is often what he has not said that is troubling. This week, for example, he refused to say if he agreed with UN Secretary General Ban Ki-moon's description of Israel's attack near a school as criminal. In responding to the crisis, Mr Cameron has also continued to emphasise Israel's right to act and Hamas's refusal to end its attacks.

The Prime Minister is right to criticise Hamas, a group that is pledged to destroy Israel, and to call on Hamas militants to cease firing rockets into Israel, but he should also be going much further in criticising Israel and its blockade of Gaza. Negotiations to end this latest conflict could soon be underway in Egypt, but they will not be successful long-term as long as the blockade and the de facto imprisonment of Gaza's citizens continues. The UK Government has yet to send a sufficiently robust message to Israel to that effect.

There is also unlikely to be a permanent solution in Gaza until the international community, with the UK playing its part, puts more pressure on both sides. Israel and Hamas may be able to do a deal in Egypt in the next few days and find support for it among their own people, but unless such a deal addresses the fundamental issues such as the ongoing siege and the Palestinian claims to statehood, the chances of another war breaking out are high. It is not pessimism to say that; it is simply realism about regions where entrenched terrorism exists. A solution in such places is never, in the end, found through escalating the violence, but through both sides declaring an end to it and entering talks with a willingness to compromise on the important issues.

Such a prospect remains far off in Gaza and is unlikely to move closer while leaders such as Mr Cameron seem to go easy on one side. Baroness Warsi thinks such an approach is morally reprehensible and feels she had to resign.

Her former boss must now consider whether the UK, as a member of the international community, can make a better, stronger contribution to finding a solution.