That is an extremely inaccurate statement especially considering that most of the modern welfare that we deliver today was introduced as part of LBJ's war on poverty in the 1960's.
1. Wealth & Welfare is one of the only books that actually tries to determine all social welfare spending and compare it by country. Guess what? The US spends much more on social programs aimed at the poor than every other "enlightened" european country other than Norway. Additionally the authors make some compelling argument that US poverty numbers are quite inflated based on the old metric of claiming a certain percentage below median income equals "poverty" regardless of actual living standards.
So why is our standard of living so much lower in comparison? Our quality of education is suffering, our happiness index is in the toilet, and our wages have stagnated over the last 30 odd years? Certainly you could make a good argument about the efficiency of our implementation of welfare, but when you consider past history, and compare ourselves to the other 1st world nations, you can't make an argument against the concept of welfare itself.
On top of that, I believe welfare, minus medicaid, only accounts for around 2% of our GDP. Even if we were to nix all welfare programs completely, throw out food stamps, and boot everyone off the dole, it wouldn't a thing to help our so called debt concerns. In fact, it'd probably make them worse, since our welfare subsidized corporations, such as Wal-Mart, don't pay a living wage for their average worker, which means they'll have to get an extra job, won't have time for anything else besides throwing all their energy at barely treading water, which will equate to less money flowing through the economy.
2. I would like to know where you are getting your data from, because AFAIK there is no data available more recently than around 2013 time-frame.... at which time we could see that compared to 2003 the United States was spending more in every single category (SNAP, Medicaid, Medicare, WIC, CHIP, supplementary energy assistance) with the exception of assistance payments to states... which lines up with the Federal governments goal of pushing states into the margins in this area and becoming the primary "care provider" for people who are unable to take care of themselves, from birth to death.
Mostly I'm counting everything besides Medicaid and Medicare, which we do spend a relatively good chunk of cash on. Generally speaking, we spend a bit less on welfare assistance than we have previously. Yet somehow it's considered a massive, MASSIVE burden on the average taxpayer, who ultimately only contributes around $100 a year towards it.
3. The US does spend roughly 50% of their budget on military programs, however where-as you want to cut military spending and then re-distribute that to help "the poor", many people are in favor of cutting military AND OTHER spending and paying down our insane debt!
4. Many Americans, especially those who've never served in the military don't understand the need for military spending because they don't see the results in their day to day lives.... here's what the military does in a nutshell - the military keeps people from coming here or going somewhere else friendly to Americans and their business interests and taking all of your stuff... which is something that countries with weak militaries have found out about now for many thousands of years. Rome didn't fall because the Goths and Vandals were better then them technologically or even tactically... they won because the average Roman had lost the will to fight them. Towards the end of the western Roman Empire men of military age had gotten into the habit of cutting of their thumbs so they couldn't hold a sword, insuring they couldn't be pressed into military service. Similar to the draft dodging dirty hippies of the US circa 1970.
Don't look at it as just helping the "poor". Look at it as using our taxes to strengthen the nation as a whole. Despite the fact that our economy has only grown over the last 100 odd years, our infrastructure is crap, education is blah blah blah, and so on and so on. So what's the one thing that's increased by exponential amounts since the 60's? Our military budget. As you said, it makes up a full 50% of our budget. And of course there's the old chestnut about us spending more on our military than the next 10 countries combined.
Now I'm not advocating we rid ourselves of our military. It's kind of a necessity. Nor am I saying we should do cut military benefits or personnel. Hell, those barely make up a fraction of our military costs anyway.
Most of our budget goes towards the people who make all our cool toys. While this is also an absolute necessity when taken at face value, because we have to maintain our technological advantage, the sad fact is that we're not spending our money efficiently. Let's take the infamous F-35, which cost we the taxpayers somewhere between $800 billion and $1.5 trillion.
...for what? The research required to build a new model of plane that could be generously described as "decent enough". The cost of this research almost equals the amount of half the money we've spent funding the war in Iraq. For the cost of this one middling to decent long distance fighter jet, we could practically have sent an entire generation of kids through 4 years of college.
Some of these kids would've pushed their education farther, became our next generation of engineers, and figured out how to build a goddamn futuristic fighter jet for less a trillion dollars. NET GAINS ALL AROUND!
Our military industrial complex is one giant hole we throw money into, and sometimes...
sometimes...it tosses a little trinket back at us as a half hearted thanks.