According to
just4today, we can look at the source of the article in the OP (Fox News) and go no further.
I'm not a student of Roman history, but would one of those factors be spending too much money on unnecessary wars?
Yes, to some extent, but do keep in mind that such things are not necessarily one way streets: Relative declines are not necessarily due to actions or inactions of the "decline-er" but are often due to actions of "ascend-ers". And that's very much a potentiality for us here in the US: We could do
everything "right" but if other countries (let's say China and India), who in the past have arguably been laggards (quite frankly), suddenly start doing more things "right", then our relative positions will tighten up, and for anything that is substantially a zero-sum game, that cannot help but seem like we're "losing ground" -- but it is because the competitors are catching up.
It is a lot easier to catch up to the leader (than to pass him/her). Our "international competitors" have the advantage of coming from behind, with us having done all the hard work of paving the way. And even though we can still forge new paths, because we're that good, what we "lose" is the ability to exploit the paths we've already forged, as much as
we have exploited them in the past, just because we now have to share those benefits with these "international competitors".
So what people are perceiving as declines may simply be a reduction in our ability to exploit the world as much as we have in the past.
That isn't to say that spending too much money on unnecessary wars isn't a factor. My point is that it is not necessarily the only thing going on here.
Under Obama's rule, the Dems need not worry about wars since our military will be decimated.
On the contrary: Obama plans to
increase the size of the Army and Marines.
Beyond that, by replacing a lot of "warring" with some diplomacy, Obama could end up substantially strengthening American's position. It costs a lot less to build up strength in peacetime than it costs to actually wage war. "Operating costs" (as it were) are much lower in controlled circumstances (training) than uncontrolled circumstances (warring). Beyond that, diplomacy can shift some of the costs of defense off of our taxpayers and onto other countries that also benefit from security. GWB has made us substantially a pariah nation in the international community, so basically we're forced to carry the costs of security of the regions within which we have interests more and more solely on our own backs. The more that can be reversed (over time, of course), the better it is for everyone.
Well then I suggest you study it. Rome became the greatest empire of it's time through conquering other countries.
That won't work well anymore. There is an international community that would take action against the United States if it ever became expansionist in the same manner as Rome was. So that's just a red herring.
And another thing: Rome paid for its warring by taking the costs of it from the conquered. Why hasn't GWB paid some of the costs of his war in Iraq with Iraqi money? Obama has suggested this.