1 Climate change and other enviromental issues
2 The rise of the right (increased poverty, inequality etc are included in this)
3 War, of which we're going to see a lot more thanks to 1 and 2

Obliteration of nature and the life support systems of the planet.

Failure to prepare for natural disasters like supervolcanoes - billions could starve to death if we don't start systematically storing food.

Rogue states and powerful terrorist groups driven by hateful ideologies cooking up weapons of mass destruction - it's hard to see how we're going to be able to prevent the invention and release of genetic weapons and robotic devices that could be used to carry out genocide if they have biassed AGI running in them.

Tribalism over multiculturalism -- this gave us he who shall not be named - this will be the start of the next civil war -- or even WW III -- See Syria and the whole middle east.
Short sightedness -- do a little today to prevent a major crisis tomorrow ... ie, global warming -- Play the long game - not the cheap win.
disrespect of education and facts -- Facts trump your opinion - statistically valid numbers trump your singular experience(which may be true, but not statiscally significant)

I class religion in the tribalism problem - as is racism, sexism etc.

Playing the long game -- I haven't seen the USA do this successfully in my 70 year life!! but China seems to excel at it -- not a good outlook for the USA in the long run.

Disrespect of facts -- Fox news anyone? -- playing to the emotions of rubes is easier than critical thinking based on data and facts.

Religion
Too Much Goverment
education

I say Religion cause it seems like all they do is fight each other on who is right
and if you do not belive or follow thier beliefs you are evil.