"I do not believe that we would make the world a safer place by Britain not being involved in defence expenditure here nor in responsible defence exports." Jack Straw
By Mark Davies
BBC News Online political reporter
The move enables "heads up" cockpit displays for US-built F16 fighters to be sold, even though the aircraft are destined for Israel.
Opponents believe there is a risk that the F16s fitted with the British-built "head-up" displays could be used against the Palestinians.
But speaking to BBC News Online, Mr Straw said the decision to change the rules had been taken many months ago and that Labour critics were wrong to say it had been rushed in order to satisfy US business demands.
The foreign secretary also defended arms sales to Pakistan and India despite tension in south Asia.
Mr Straw also said it was "too easy" to say that the government puts business interests ahead of an ethical dimension to policy.
He said: "Our arms exports are more strictly controlled than almost any other country in the world, along with the United States and Sweden."
He added: "We have clear criteria predicated on the basis that we will only export arms when the criteria are met."
Straw: Decision took many months
He said the criteria needed changing because they did "not take full account of a very fast changing situation".
This meant "defence industries these days are much more akin to multi-national, in this case, transatlantic, assembly lines, in which different countries are contributing components, in some cases two components, to put into final use equipment".
"What I have done is publish factors which will now be taken into account for the export of such components.
"They include whether the receiving country for the incorporation of one set of parts into the final product itself has a good export control license system.
"Now it happens that the United States does."
He said he could understand why some people found it difficult to appreciate why the UK was involved in arms sales to India and Pakistan and in deals which could lead to UK-made parts being used in aircraft sold to Israel.
But he added: "On the other hand we are not a pacifist country and I do not believe that we would make the world a safer place by Britain not being involved in defence expenditure here nor in responsible defence exports.
"I have thought about this by the way, because my father was a concientious objector who went to prison for his beliefs in the war.
"I have great respect for him but I have really thought it through and I don’t take that view."
Current guidelines ban exports of equipment if there is a clear risk that they could be used for internal repression or external aggression.
Labour MP Donald Anderson, who chairs the Commons defence select committee, said the new rules should be debated by MPs.
The UK government complained in November 2000 about the use of British made components in tanks and helicopters used by the Israelis in the territories.
Conservative foreign affairs spokesman Michael Ancram urged caution over the changes.
Menzies Campbell, Lib Dem foreign affairs spokesman, described it as a "dispiriting" response to events in the Middle East.
Labour’s Brian Iddon, secretary of the Commons all-party Palestine group, said: "I am very disappointed that we are aiding and abetting the Americans to attack the Palestinians."
Labour MP Alice Mahon warned: "It is outrageous, given what is happening in the Middle East."