The war on some drugs has shown to be a failure.
So has every other war against every other crime. Does that mean we should just make it all legal so we don't have to spend money? If not, just exactly where do we draw the line?
Perhaps, but you fail to say why.
So, I'll tell you why.
"The War on Drugs" is largely regarded as a failure for several reasons, the following (in no particular order) among them:
"The War on Drugs" is, at root, a war on human nature, which has 10,000 years of history testifying to its insatiable appetite for debauchery. Well, humanity can't even keep its potty mouth in check; so, who's the idiot who ever thought we could win a War on Drugs?
A substantive portion of the perception that the "War on Drugs" has failed (or is failing) as owing to a near-complete lack of knowledge as to how completely wrecked our civilization would be if the drug traffic went unchecked. In light of the first point, this consideration is decidedly NOT a plus for the Libertarian arguments.
The War on Drugs focuses only on one side of the problem: supply. This is a doomed strategy, as economics dictates that; where there is demand, supply will continue to exist despite all efforts to stop it. Without a campaign against demand that is at least equal in power to the campaign against supply, the entire effort must be regarded as a stillborn concept.
That stated, Libertarians would do well to take a lesson from the disarray, disunity, and general lack of economic and social progress experienced in Israel during the time of the Judges, and note the principle cause given in the biblical text:
25 In those days there was no king in Israel; everyone did what was right in his own eyes.
— Judges 21:25 NASB
Not until Israel dispensed with this libertarian streak and opted for a monarchy did they begin their ascent to their Golden Age under David and Solomon.
Why?
Only the force of a strong national government that elevates the status of religion in public life can place sufficient impetus upon the individual to live in righteous self-governance, but that only indirectly, and this is not the best rout as it increases, rather than decreases, the role of government. And, lest I be misconstrued, not just any old religion, either. Note again from Israeli history how their Golden Age fell to ruin and exile as they increasingly embraced pagan beliefs, and fell to the worship of mere idols.
No, the surest rout to liberty is that the people would, of themselves, aspire to individual, righteous self-governance, as God defines "righteous." The more righteous self-governance imposed by the people upon themselves, the more hands-off may be their national government.
That is why John Adams said, rightly, "Our Constitution was made for only a religious and moral people. It is entirely unsuitable for any other." To put a fine point on it: no individual who refuses to govern his own self in righteousness will be suitable as a citizen under The Constitution of the United States.
And whence derives the impetus to righteous self-governance?? In answer I commend to you the experience and intellect of no less than George Washington, himself:
Of all the dispositions and habits which lead to political prosperity, Religion and morality are indispensable supports. In vain would that man claim the tribute of Patriotism, who should labour to subvert these great Pillars of human happiness, these firmest props of the duties of Men and citizens. The mere Politician, equally with the pious man ought to respect and to cherish them. A volume could not trace all their connections with private and public felicity. Let it simply be asked where is the security for property, for reputation, for life, if the sense of religious obligation desert the oaths, which are the instruments of investigation in Courts of Justice? And let us with caution indulge the supposition, that morality can be maintained without religion. Whatever may be conceded to the influence of refined education on minds of peculiar structure, reason and experience both forbid us to expect that National morality can prevail in exclusion of religious principle.
— President George Washington, Farewell Address, September 19th, 1796
There is no conflict between the concepts of maximum liberty, and the scriptural declaration that "[Messiah] shall rule [the Nations] with an iron scepter," which speaks very poignantly of a powerful, top-down global government. The rise of a people whose hearts are turned toward righteous self-governance in the sight of God is THE only explanation as to how the two are brought into harmony.
Let whatever outcry is aroused by these arguments will serve as further insight into why "The War on Drugs" is failing.