This is the question posed by Professor Hanson. The answer: of course we can.
We just have to decide to really fight them first.
The first step is to remember what war is supposed to be about: it is an existential struggle, in which one side attempts to impose it's view -- on all things -- it's culture, it's values, upon another. Historically, there has only ever been one way to do this with a measure of guaranteed success, and that has been to engage in a war of annihilation, a contest in which one side is willing and able to inflict untold, unspeakable, unbearable suffering upon the other.
For human beings are stubborn things; without suffering intense hardships. without the heartbreak and emotional strain that comes from watching their children starve and their loved ones die horribly, without the mental scars that form in the aftermath of some great catastrophe, they very rarely either change their minds or learn their lessons. The Wars that have left the longest impressions and brought the best peace, have been the ones where one side was willing to be as inhumane to the other as possible during hostilities, where the experience of war and occupation has brought the more rational thinkers into line.
India, Japan, South Korea, the few other non-Western places where Western Democratic and Capitalist culture has taken root were all the scene of exactly what I'm talking about.
India had been occupied by European powers, the French, Dutch, Portuguese and English, whole or in part, for centuries. During that time there was war, there was dissent, there rioting, and there was always reprisals. often bloody and ruthless reprisals. But now India is an independent nation, and becoming an economic and military power to reckon with in Asia. It has learned, the hard way, that the Western Way is best; consensual government, capitalism, democracy, secular rationalism. Millions died, often horribly, from war, starvation, and disease before Indians finally decided that their old ways were not perhaps the best ways, and gave up certain aspects of their culture -- the ones that kept them from joining their former European overlords in the modern world -- and accommodated and adapted Western Cultural practices.
Japan had been bombed flat by American B-29's. Atom bombs smashed two of it's largest cities. Millions died in battles on land, sea and air across the vast spaces of Asia and the Pacific, and millions more died of starvation, disease, and the inhuman work demanded by their own Imperial government in the course of the Pacific War. The Japanese people were exhausted, and harried to continue to fight, even to the death. Japan's leaders finally decided that continuing to fight for an Empire that could no longer be justified, to continue trading lives to continue the charade that Japan was a nation on par with those in the West, was a losing game. The West had proven it superiority; the proof was in burned Japanese cities, and starving peasants. The Japanese accepted occupation and an imposition of Western ways.
South Korea was the scene of some of the most intense fighting of the Cold War. It, too, was overrun by foreign powers, Chinese, Japanese, Russians, Americans, and had suffered from war and strife for centuries. the Civil war that erupted in 1950 between democrats and communists was yet another tragedy in a long line of tragedies for the Korean people. The destruction was great, the loss of life, greater still, and the misery of the people was such that many of those who initially supported the communists switched sides, or fought with the Americans and their Western Allies, to create a better Korea operating in most respects much like any Western nation.
Democracy is not like a piece of software: you don't download a program or insert a cd into a culture and have it change immediately and integrate itself into the civilized, modern world. Quite often, the main stumbling blocks to that sort of integration -- religion, culture, tribalism -- have to be overcome first. Since talking people out of their old cultural bugaboos is often a waste of time, the best way to change them is to beat the snot out of them, and put them into the proper frame of mind to earnestly embrace a change.
The American politician;s mindset of "Inside every ______, there's an American dying to get out!' is a load of rubbish. The idea that if we "give freedom" to people who have no idea of what that is, what's good for, or how to use it will result in a better world, is also a load of horse crap. if you want to change your enemies, and make them your friends, you must do two things:
a. Destroy their culture, or at the very least, make it clear that your own is infinitely superior.
b. Make people suffer so that the impetus for change is created, and becomes sincere.
Otherwise, we're wasting money, time, bullets and lives. If you're not going to do nasty work, to destroy things and kill people, then keep the troops at home.
The reason we don't seem to be "winning" anymore, is because the people who make the decision to go to war -- and to a large extent, the people who actually do the fighting -- have forgotten what war truly is and what it's good for. They live in a La-La land of political theory and discredited notions of "Limited War" surrounded by a penumbra of domestic politics, public relations, media scrutiny, and the desire of diplomats to be seen as 'doing something' even when they know they can't achieve a goddamned thing.
War is a messy business, and it is a terrible thing. It's also the most effective instrument for change humanity has. Unfortunately, the ability to wage war has often fallen into the laps of truly stupid people.