Julie Marionneau is a Research Fellow for Policy Exchange’s Judicial Power Project. Professor Richard Ekins is Head of Policy Exchange’s Judicial Power Project and Professor of Law and Constitutional Government in the University of Oxford.

The next Parliament has to get to grips with the problem of lawfare. UK forces fight as they are trained, in compliance with the law of armed conflict (the Geneva Conventions and service law). However, this body of law has been steadily displaced by European human rights law, which has been incorporated into our law by way of the Human Rights Act 1998. Enemy combatants and others can litigate to disrupt operations while UK forces are still in the field.

These developments undermine operational effectiveness and put coalition operations in doubt. As General David Petraeus pointed out at a Policy Exchange cross-party event little over a year ago: “The growing ‘judicialisation’ of conflict should concern the UK — just as it concerns me… the very special relationship between our two militaries, which has been built over decades of serving together in the hardest tests of battle, could be put at risk by the present situation.”

Many returning service personnel, who served with distinction in Iraq and Afghanistan, have had their lives blighted by a seemingly endless cycle of investigations into allegations of wrongdoing. And many who served in Northern Ireland now face criminal proceedings in relation to incidents that took place decades ago, incidents already investigated, often more than once. This is a failure of basic fairness to those who have served, as the Defence Committee has recognised. It is likely to have a damaging impact on the morale and culture of UK forces now and in the future.

Policy Exchange has helped bring this problem to public attention in a series of reports (The Fog of Law, Clearing the Fog of Law and Protecting Those Who Serve, published in June this year. The Conservative Party committed to act in its 2017 manifesto, promising to protect “armed forces personnel from persistent legal claims, which distress those who risk their lives for us, cost the taxpayer millions and undermine the armed forces in the service they give”. It promised further that a Conservative government would ensure that “British troops will in future be subject to the Law of Armed Conflict, which includes the Geneva Convention and UK Service Law, not the European Court of Human Rights”.

Some progress has been made, but not enough. While the Government has rightly committed to derogate from the European Convention on Human Rights in advance of future operations, a future government would of course be free simply to adopt a different policy. The next Parliament should consider reinforcing this commitment by legislating to require the Government to derogate in relevant circumstances. But it should also consider restoring the primacy of the law of armed conflict – the body of law that should govern military action – by amending the Human Rights Act to limit its extra-territorial application.

This amendment would restore the originally intended scope of the Act. It would prevent further litigation in UK courts challenging operational decisions abroad and would enable the Government to bring to an end the cycle of ongoing investigations. It might well lead to conflict with the European Court of Human Rights in due course. But should not the next Parliament be at least as willing to protect those who serve in the armed forces as previous Parliaments have been to maintain the disenfranchisement of those who are serving time in prison?

In relation to those who served in Northern Ireland, the problem is somewhat different. But it is not intractable. The Human Rights Act should be amended so that it only applies to events arising after the Act came into force in October 2000. This would restore the scope of the Act as originally intended and would prevent the Act applying retrospectively to the Troubles in Northern Ireland.

Parliament should also consider enacting a package of procedural protections in order to limit the risk of former service personnel being unfairly treated. The protections might include a statute of limitations, which would prevent investigation or prosecution of old allegations unless and until a court agrees that truly new evidence has come to light and that further official action is in the interests of justice. Parliament might also prohibit prosecutions of UK forces without the consent of the Attorney General of England and Wales.

Finally, in relation to allegations that concern whether force used in defence of others or to perform an arrest was reasonable, which is often a matter of fine judgment and is difficult to determine decades after the fact, Parliament should consider prohibiting prosecutions unless the Attorney General for Northern Ireland certifies that in his view there was no honest belief that the force used was necessary. This would be a useful filter. Taken together, this set of measures would help restore fairness without preventing prosecution or investigation where truly warranted.

The challenges associated with lawfare are not unique to the UK – even if the unfair treatment of veterans and service personnel has been particularly acute here. But some other countries – including the UK’s allies and adversaries – are better equipped to respond to them or to exploit them. During the next Parliament, a comprehensive counter-lawfare strategy should be developed to restore the operational effectiveness of UK forces before the next major military commitment.