To want my husband to take up a martial art to develop his confidence?

It isn't. IMO Aikido is not particularly useful for self defence as it is too difficult for the average person to master. People who take martial arts for self defence purposes would benefit from a simpler approach.
I have tried most of them and found kickboxing to be the simplest and most confidence building.
It's not true that all martial arts classes teach you never to use the techniques outside the class. You're taught you can use them for defence but not for offence. So please ignore that prohibition about not using them outside of class and go ahead and sign up. Ask your h if he wants to sign up too, but be aware that it won't make him somebody he is not. As you say, it might at least boost his confidence and you can both get some exercise in.

I did martial arts for years and met many people from all walks of life. I'd suggest he tries CBT to help him make peace with his past, for his own benefit firstly.
I'd also suggest both of you try a martial art. Taekwondo has become popular recently. It would help with many aspects, his confidence, making friends or atleast realising not everyone is an idiot. I was maybe lucky in my groups but we all supported eachother like a mini family.
And I 100% would use my skills as a black belt on someone in the street to protect myself. Even though it would work against me in court if I use unnecessary force, due to my training.

My view is, you should avoid fighting if you can, but if you can't, well, what's that saying... Better to be a soldier in a field, than a farmer in a war. Something like that. I'm fully confident in myself in a fight with a man as they're who I trained against but not under any illusion that someone with greater body strength has the upper hand if I don't move first and fast. They should teach you self defense techniques like for example with a baseball bat, don't avoid it but get closer etc. i think it's always a good thing to know how to disarm/manipulate someone with a knife/weapon. But if he's not confident, he's got no chance.

But the main thing is, you never know what the other person is carrying if it comes to being physical. It's awful that anyone should do this, but keep a spray in your bag. Hairspray or something that will sting their eyes to give you a chance to avoid further conflict.
100% if he's ready to, he should seek therapy regardless of anything else.

One person or a male/female couple doesn’t stand a chance against a group. No amount of self-defence classes are going to alter those odds.

Agree with the consensus that if you want to feel he has your back and can protect you then the best things he can learn are how to de-escalate situations and how to get away from them.

It's highly unlikely that he (or most people) would ever be a match in a fight with someone who really wanted to do you violent harm.

Building up his confidence should be an entirely separate matter to a hypothetical fist-fight and depends mostly on whether he wants to tackle it and what kind of thing he thinks will help. If he's interested in taking up a martial art by all means go for it.

'Very timid' doesn't sound like an attractive trait at all in a man. Nor does crossing the road to avoid some teenagers.

Not sure if a martial art is the answer but I'm not sure I'd want to be with someone like this tbh

Which martial art do they do?

All my step children who are black belts in karate say that they feel much safer.

One of my step sons is below average height and he says that his skills mean that he isn't intimidated by bigger guys.

It also meant that he wasn't bullied at school and that he could protect his friend who was being bullied.

I think as long as you're willing to learn it too it won't do any harm.

But I will say, some people are slapless. They might run into a burning building to save their loved one, or leap in front of a bullet, but they will never be able to deal with physical confrontation.

It is also probably true that men who are confident to get involved physically are more likely to get stabbed than ones who back down.

You can use it to protect yourself

My husband is a black belt in karate as are his children.

His daughter was able to use her karate when she was groped.

You should both try karate. It is an amazing skill to have.

My husbands teacher was was able to use his karate when he was attacked. The police didn't do anything to him.

Martial arts isn't great against street fighters. You have to train long and hard to be really good. It is more difficult as you age. We were taught blackbelt meant you were now a beginner ready to understand the art.

Getting away is the first thing taught to children in lessons.

Sparring is a different beast and not everyone is suited to it emotionally. It can be intimidating.

However, I think taking classes together is a great idea regardless. It does help with confidence in general.

Look up the Gray Man books by Matthew Dermody. Gray Man is the philosophy of not drawing attention to yourself as a form of self defence.

You need to see a therapist, good grief poor man

He is a gentle-man - it is who he is - it is who you married and the person who fathers your children.

My late OH would go out of his way to avoid conflict - I did not see that as timid, but rather as pragmatic and sensible. I loved him for who he was.

You want him to be a protector for you; but that is not his style. I am sure there are many other ways in which he supports you.

You cannot make him someone he is not; and it would be unacceptable to try and mould him to your wishes. He will quite rightly see your attempts to get him to martial arts classes as manipulation and as a criticism of who he really is.

I know what my OH would have said if I had tried to get him to do this!

Can we spar against each other as practice?

I know you've said you've had enough of this thread OP, and that's fair enough, but I really, really wouldn't recommend sparring against each other outside of the dojo until you've had at least a years' training (or maybe two)

I don't want to be insulting, but every newbie/lower grade student goes through a phase of thinking that a few classes have given them greater skills than they actually possess. And if a couple spars, without the watchful eye of the instructor, feelings as well as noses/limbs etc get hurt.

I'm a large guy, but I'm now 55. Because of where I grew up I have been involved in lots of violent situations, plus going to football in the 80s and 90s. I was brought up to have a sixth sense about violence and I know actively avoid situations where I could potentially be in a violent scenario. That doesn't make me any less of a man.

You seem to think that your husband needs to stick for for you and perhaps if someone attacks you he should. But if it is a verbal attack, disgusting as that may be, the best course of action is to ignore it and when safe report to the police.
I know you would be upset to be racially abused and I'm sure your husband would be too...but I had a friend who got into an argument about an £8 yes £8 drug deal in the 1980s and he was murdered.

Martial arts would probably help to build up his self-confidence a bit. OBVIOUSLY he isn't going to turn into Chuck Norris, but knowing that you could defend yourself if you absolutely had to is a good thing.

I used to do krav maga. I was rubbish at it, but I loved doing it.

My children do a martial art - Kuk Sool Won - my daughter (10) should get her black belt next year, if all goes well, after 4 years of training. My #1 reason for signing her up originally was self-confidence, followed by discipline, respect, flexibility, balance and coordination. Self-defence wasn’t even on my radar!

Absolutely sign up for classes, but don’t expect to actually use it in self-defence - for a start it will take a few years of training before you’re actually any good!

Do you like it when people "suggest" you take up things that you have no interest in, but that they think would make you a "better" person?

To be realistically able to use it effectively for defending you or himself he would need to train for years, unless he really took to it at best it would not be effective and at worst put him in a position that he could have the confidence but he wouldn't be able to execute it well enough.
As a general confidence builder, it is great though.

He needs therapy.

It take years of skill discipline and training to be good at Martial arts. Even then there is no stopping a heavy right hook or a gang of teenagers.