National Debt: It takes money to make money... put average social security lifetime payout into a diversified index fund upon birth when children are born. Each child would earn interest like the wealthy do over time, be less dependent on government assistance, and we would be proactively addressing needs vs reactively.

Frankly, for hunger in America simply make it illegal for companies to produce a certain quantity of food waste. Otherwise facing a hefty fine.
This could possibly solve multiple flood related problems, such as food waste and obesity. Give companies incentive to donate food to shelters and other places that could use food.

Return to the tax rates we had from world war two until Regan. Re-Regulate banking and tax all stock trades at 1%. Universal Health care for all citizens. Living wage laws and force banks to allow any homeless veteran to live in any foreclosed property with a route to owning it with low interest VA guaranteed loans.

Put those closed bases and smaller closed facilities to use as veteran communities. Aim to make it as self-sufficient as feasible, thus giving those vets purpose and something to do. This would include having a VA clinic on site. Certainly include an agricultural component, with both food crops and livestock.

You know the story.
There was an old women
Who lived in a shoe.
She had so many children
She did not know what do?
Answer- So she kicked the old man out.

To solve those three Nations problems.
We need to kick the bankers and politicans out, like the women did in Iceland.

Institute a progressive tax like most other 'civilized' countries. Those with the means need to provide more.

All three lots of nuclear bombs

Homelessness is very easy to cure without our government doing anything.
If you know of any veteran that wants a house have him contact me.

My initial humorous response is an adaptation of A Modest Proposal to somehow include all three (because I'm a jackass sometimes)

My serious response...homeless veterans.

Scenario 1: the government buys up many of the derelict houses left on the market for years after the real estate bubble burst. Those homes are then repurposed into rent-controlled housing for veterans and their families. I like this scenario but it seems unrealistic, largely because it requires a lot of capital and/or imminent domain issues on the front-end and...well the National Debt is one of your other topics.

Scenario 2: the government purchases land and either develops it similar to the way they did after WWII or engages in a 'habitat for humanity' style process whereby returning veterans collectively build a community. This seems unrealistic both for capital reasons as well as...it's kind of messed up to ask men and women who are returning from combat zones to subject themselves to construction sites to build their own homes basically, but the self-sufficiency aspect may appeal to some.

Scenario 3: okay this assumes I adequately understand the principles that govern federal spending. If I don't this falls apart pretty quick as a result. Okay, the government allocates a certain amount or percentage of the annual budget to (in this case) the military. A bill will have to be passed as part of the budget process to make this happen. These bills include earmarks for contracts with companies, and taking money from a pool of spending (education) and allocating it to another pool (agriculture) is not allowed, without another cycle of voting on spending bills, if at all. And if your department does not use its entire budget, it will have a smaller budget next year.

So the military includes, as part of its spending bill, an increase in the line item or bill which handles budgetary spending for military housing, puts the psyops people to work crafting kickstarters and fundraisers and benefits and other charitable events to help raise money to house veterans. Where that money needs to come from within the defense spending budget as a whole is beyond me, but I'm sure someone somewhere has been padding inventory to pad the budget. I don't mean criminally, necessarily, but someone has kept an eye on making sure the budget stays healthy, so some of this can come from the padding (is this cutting pork barrel spending by diverting it to a relevant and valuable expenditure? I'm honestly asking that's one of those terms that always twitched me out.) Contracts with contracting companies can be engaged as part of spending to do the building. This seems like the winner for me, but something in my mind is telling me I'm overlooking something.

Take half of the current funds slated for Defense and put it towards all Veterans. Build city gardens to feed the homeless, the children, and reduce the food waste. Stop our elected officials from exacerbating the national debt. Only use the money obtained by taxation and refrain from over taxation. Make all taxation fair for all, including the rich. Reduce the pay for the representatives in D.C. Impose term limitations for Senate and House seats. Make Marijuana federally legal and tax it and use that money locally to improve infrastructure and schools.

Stop giving billions in aid to Israel., concentrate on your own people.

Stop going into other countries and making war there that will save billions.

National debt ? Have a massive trial trying all corporate and war criminals , when they are found guilty of acquiring money and assets through criminal activity , confiscate those and assess huge , beyond total fines to be used to pay the legitimate debts ! Child hunger , Homeless vets ? Tax the rich to death or at least enough to solve these problems and most others.
Then EAT THE RICH ! Or feed them to the hungry critters at the animal shelter , ha .

For national debt, I'd make hemp a main crop that was federally grown and have the government use the profit from the sale of raw hemp only. All other steps below raw harvest, the refining and processing and products created, would be citizens. Use the profit to pay off the debt and once it is paid off, the profits would go to the things our taxes pay for.. and any profit beyond that would be divided among the people. I'd make it a 20 year plan with complete transparency and if it proves to pay off our debt and work for the people, they could vote to keep it going or have the business of producing raw hemp returned to the people and have taxes reinstated.

For the other two, Thunderdome?

Oh my gosh, this would be too long a post. However, one could actually start with one and end up fixing all three.

For starters, no matter the choice, I would start by cutting the military budget by 35% and taking a portion of that money greatly increase funding to the VA. I would then take what was left and add it to the amount we spend on health care and institute a universal health care system to greatly lower the cost of health care to the people. I would increase corporate taxes to 80% and increase the tax on the estate tax to 90%. Most would go to pay down the debt while the rest would go towards school programs, better funding of the education system, research in overhauling the curriculum to be more efficient and better effective. I would implement tuition free post secondary education. I would wipe away all outstanding student loans. I would implement programs that would mirror European labor union laws and make it a law that labor must have a representation on company boards. People would bring in more take home pay allowing families to be able to spend more money of food and groceries. I would actively research ways to lead in education, health care, overall happiness, and work on ways to reduce stress of the people. I think it could be done if everyone worked for the greater good of the many.