Two months ago my sister-in-law bravely travelled to the Gulf to help in the battle against Islamic State (Isil). Her three year old daughter stood in Portsmouth harbour and waved her mummy off for nine long months.

We now live in an age where women help run warships. For Lt Cdr Victoria Percival, or Vic, as we call her at home, is the Marine Engineering Officer (MEO) of HMS Defender, a Type 45 Daring Class Destroyer. She is in charge of a large team of technicians, and responsible for the ship’s engines, power generation capabilities, water, cooling, hydraulics systems and hull. Essentially she ensures that the ship can function as the captain, and by extension the Government in London, wishes.

"Society still consistently struggles to see women as saviours or defenders."

Right now that means supporting France’s bombing campaign against Isil by providing air defence cover for the French carrier Charles de Gaulle. I would be lying to say her departure hasn’t prompted wider family discussions that may not have happened if her husband, also a senior officer in the Royal Navy, had been deployed. Humanity has had less time to become accustomed to the sight of a temporarily single father managing while his wife is away at war.

But my brother-in-law himself didn’t bat an eyelid, as is the impressive military way. Nor have we ever questioned Vic’s ability to defend this country – on account of her sex or anything else. She is supremely capable and we are incredibly proud. The realm can sleep easy when people like my sister-in-law are helping implement defence.

And yet, society still consistently struggles to see women as saviours or defenders.

Consider this scenario; a fire begins in your home and your call the local brigade. More female firefighters turn up then male. Do you a) panic and demand a new crew? b) Start praying for a miracle? Or c) Let them do their job?

Blue Watch at West Norwood fire station making history Credit: London Fire Brigade/ London Fire Brigade

I ask this because a few days ago a London fire crew made history by having more women than men on shift for the first time in the Brigade’s 150 years. Blue Watch at West Norwood happened to have five women and three men on duty. The subsequent photo of the female-dominated crew on a tea break is a pretty novel sight.

However, while Watch manager Sally Coxon was proud, she lamented the nation’s outdated attitudes: “We will get off the fire engine and members of the public will say ‘you’re a woman’ or ‘do they let you ride the fire engine?’ A lot of people don’t realise we do exactly the same job as the guys.”

In the Armed Forces some of the old guard have missed that same memo. Earlier this week Admiral Lord West of Spithead spoke of his “nervousness” about British female soldiers being allowed to fight on the front line from the end of 2016. Worrying that the lifting of the ban will weaken our military, the peer trotted out predictable fears over women’s poorer upper body strength and ability to kill.

Brigadier Moffat - formerly the most senior woman in the Army

He is not alone. Far from it. Last year, when Colonel Richard Kemp, the former Commander of British forces in Afghanistan, wrote something similar about women lacking the killer instinct, Brigadier Nicky Moffat (formerly the most senior woman in the Army) described his words to me as “sexism dressed up as concern”.

Entry requirements for the infantry will not be changed, or thresholds lowered, for female soldiers wishing to join. So arguments like these are moot. Only the best men and women will continue make it into these units – just as they do in the fire brigade. To think anything else is insulting to services which pride themselves on the highest levels of training to secure the safety of our citizens.

Admiral Lord West of Spithead is 'nervous' about women on the frontline

We are increasingly used to women as bosses, bankers, doctors, sporting heroes and many other non-domestic roles. But the truth is that both sexes are yet to be comfortable with women as warriors.

Some won’t view the arrival of women on the battlefield as a victory. Feminism in its earlier forms dreamily desired peace and the overthrow of the patriarchal societies which created wars in the first place. But egalitarian feminists like myself must take pride in people like my sister-in-law, who are playing such a key role against the West’s biggest adversary.

Britain’s women are taking their places in the frontline. You don’t have to be grateful. But you would be foolish not to recognise the talents and skills they bring – and the fact that duty, and the capacity to serve, is genderless.