After last week's televised leaders' debate on international issues, I am being regularly asked for my views on foreign policy - on Afghanistan, the EU and the Middle East. A Conservative government would change the direction of current UK foreign policy. This would cover a range of issues, including:

• A more joined up foreign policy. Under Labour we have seen too much sofa government, especially on foreign policy - the prime example being decision-making leading up to the invasion of Iraq. The Conservatives would set up a National Security Council to coordinate the defence, diplomatic and development branches of foreign policy, so decisions are taken on proper information following rigorous scrutiny.
• The Special Relationship. The transatlantic alliance with the US matters. We gain immensely from the defence and intelligence cooperation, and share common values. But, Britain should be prepared to say 'no', when the national interest demands. Candour strengthens good frienships - remember Thatcher 'hand-bagging' Reagan over Grenada? David Cameron has pledged that our friendship with America will be 'solid not slavish'.
• The European Union. British membership of the EU is of great economic benefit, and there are other areas where we should support cooperation with our European partners - but on an inter-governmental, not federal, basis. We oppose political integration by stealth (Labour's policy). We were absolutely right to oppose British membership of the Euro in order to retain national control of interest rates (Lib Dem policy). We need to repatriate control over social and employment policy, to keep British business globally competitive. And we should exercise our opt-out from EU Justice and Home Affairs policy - to ensure British citizens retain the freedoms and safeguards guaranteed under the British justice system.

As a former diplomat and international lawyer, I am particularly interested in foreign affairs. International relations have fragmented since the end of the Cold War, presenting risks and opportunities. Britain remains the sixth largest economy in the world, with the ability to project military force at a distance, global links via the Commonwealth, and immense 'soft power' generated by the English language, UK universities and our popular culture. We need a genuinely global foreign policy to maximise our comparative advantage in the world. But it also needs to be more flexible, and less tied to the hip of the EU (or the US for that matter). We need a foreign policy that puts the UK national interest first, not last.

For example, Labour placed far too little value on sustaining bilateral relations - because their intangible value was not easily measured by central government targets - so we have lost clout in important parts of the world. I have lost count of the number of times Asian and Latin American diplomats have expressed bewilderment at the inward, insular, fixation of the EU and European diplomats - neglecting rising powers in both regions. A Conservative government will redress the balance.

When it comes to our military, we are long overdue a defence review. Our forces are overstretched and under-equipped. Britain must cut its coat according to its cloth - either by reducing our commitments, or increasing our defence investment. Anything less puts our troops at unjustifiable risk. Both Labour and the Conservatives have committed to retain the Trident nuclear defence deterrent. That must be right. At the Foreign Office, I negotiated treaties to strengthen control over the illegal shipping of weapons, and advised on maritime military operations. The threat of nuclear attack from the Soviet Union may have receded, in the aftermath of the Cold War. But, there are still a range of states pursuing nuclear weapons, and our efforts at stopping them have achieved mixed results - Iran and North Korea being the two most obvious examples.

In such circumstances, the Liberal Democrat plan to scrap Trident is doubly irresponsible. First, because we face diverse threats in an uncertain world - and Trident deters states who might threaten or blackmail Britain. Second, because Liberal Democrat policy is unclear as to whether they want to get rid of our nuclear deterrent altogether, or replace Trident with something else (if so what, and at what cost?). The bottom line: it is irresponsible to sit on the fence when it comes to national security.

(Mock poster courtesy of West Cornwall CF and Conservative Home).