Bob Seely is MP for the Isle of Wight.

As if the Brexit crisis wasn’t enough for Boris Johnson’s first week as Prime Minister, he now has an international crisis in the Gulf too; one that, if handled badly, may lead to conflict. As Harold MacMillan said, when asked what throws a Government off course: events, dear boy, events.

On Friday, a UK-registered tanker, the Stena Impero, was seized by Iran, one of a series on incidents in the past three months between Iran and Saudi Arabia, the US and the UK. Iran, under pressure from US sanctions, is readying to cause chaos in the Gulf.

Here are some immediate thoughts:

The UK is caught between rock and a hard place. The Iran crisis is stretching the already strained alliance between the US and Europe – and we are feeling it more than most.  On the Iranian Nuclear Deal – which is at the heart of this crisis – we are diplomatically aligned with the EU in supporting the deal, known as the Joint Comprehensive Plan of Action (JCPOA), whilst we remain deeply embedded in the US military alliance which, regardless of who is president, retains remarkable importance for us.

Second, we are paying the price for not paying for defence. Our emaciated presence in the Gulf is due to two decades of under-funding of the Navy and the Armed Forces more generally. We reaped the peace dividend at the end of the Cold War but refused to reinvest in the mid-2000s when the world became a more dangerous place. The Conservative-Liberal Coalition was a particularly shameful low-point in absolute cuts made to defence.

In the 1980s, the Royal Navy’s Armilla patrol in the Gulf had up to four destroyers or frigates (small destroyers). Then, the Navy had over 40 frigates or destroyers. We have 19 now. Whilst technology has made these vessels more powerful, we no longer have mass.

At the same time potential adversaries, be in Iran or Russia, have invested in many varieties of power, including hard power, whilst some military technology, such as drones, have become much cheaper and more widespread.

Despite this changing balance, our strategic responsibilities have stayed the same. We are trying to do the same with less as our rivals have more. Our only legally binding expenditure is on aid, which has gone up to £13 billion. Politically, in the last decade we have prioritised virtue signalling over protecting our national interests. This needs to change.

Third, warfare and conflict has changed and will continue to evolve. Two decades ago we entered the era of full spectrum warfare, sometimes known as hybrid or asymmetric warfare. This is where nations and non-state actors (think ISIS, Hezbollah, etc.) chose to use non-traditional methods to achieve their aims, either because they cannot match US technology, or because non-conventional methods of conflict are more effective in the era we live in. Iran, alone with China and Russia, are the major proponents of full-spectrum warfare. The seizure of the Stena Impero was an example of this.

Iran’s full spectrum tools also include influence or control over religious, political or paramilitary groups across the Middle East: the Houthi in Yemen, Hezbollah in Lebanon, Hamas in Gaza, the Alawite regime in Syria, proxies in Iraq and religious groups in the Gulf states. In case of further conflict, Iran will very likely initially seek to damage UK, US, Saudi Arabian or UAE targets in the Middle East, through its proxies, overtly or covertly. Lobbing a UK missile at a no-doubt empty target in Iran will achieve nothing except threaten British lives and interests across the Middle East.

Fourth, Iran wants to internationalise this crisis. It is suffering under new US sanctions since they were imposed when President Trump unilaterally withdrew from the JCPOA in May 2018. US sanctions have been surprisingly successful. However, as a result moderates in Iran have been weakened, and anti-Western and illiberal elements strengthened. The thinking from those who know Iran is that, if Iran is going to suffer, it will make the rest of the Middle East suffer too. That could mean a mix of destabilising attacks on shipping, paramilitary attacks or assassinations in the Middle East.

So what’s the answer?

In the short term in the Gulf, the UK needs to renew international and regional alliances and find convoy partners. We should additionally put in place what deterrence forces we can in local bases in Bahrain and elsewhere; another destroyer or two if we can muster it, swift boats, helicopters and drones.

In the longer term, we need to work with the US, the EU and Iran to find a way out from the ongoing crisis. In practice, that means finding a realistic set of proposals acceptable to the US and Iran that gets the JCPOA back on track. Mike Pompeo has outlined 12 demands. These are seen to be unrealistic, but there is some chance for a more modest set of US proposals being put forward that Iran could sign up to, or at least use as the basis for negotiation.

Finally, and more broadly, we need to plan for the decades ahead. We are not doing so.

In February I launched a Global Britain study with the Henry Jackson Society. In that report, I outlined some key aims: reinvest in hard power whilst ensuring that we are capable of understanding and countering full spectrum warfare; integrate overseas policy and possibly even departments; redefine aid to allow DfID funds to fund peacekeeping options; and provide for a significant uplift to the BBC World Service Radio and TV. Most importantly, the UK should develop a global strategy for the next decade and two, driven by a UK Strategy Council.

The UK has benefitted from the international order constructed after the Second World War. We need to invest to defend it. That doesn’t mean, as the predictable line of questioning on the BBC in the last couple of days put it, wanting to be the world’s policeman or boss others about, but it does mean delivering an overseas policy which allows the UK to remain a leading player in the global order, and by so doing, defend our just interests.