Did we have a practice of holding back when we had an enemy target?
Yes, but the holding back even goes beyond that, to not even making targets of them in the first place. Our posture over there has been almost exclusively static and defensive for most of the time we've been there, holding & patrolling our areas but sticking to them and leaving the outside areas alone. It lacked the kind of offensive/aggressive missions in which you go out to where the enemy is and attack. The last time we
did operate that way was soon after arrival, and it soon resulted in having them surrounded so they could all have been wiped out in hours with just a few bombing flights, but we didn't want to seem too mean, so we handed off the job to our local "allies", who let them out. No other serious moves against them have been tried since then, just marking time. Some people like to depict this as a failure to do more, but you can't "fail" at what you're simply not even trying.
You're speaking as if you have no idea why successfully occupying Afghanistan has stymied some of history's most powerful empires.
That's a myth.
Reliable records of what was happening there go back to the Persian empire in the early 600s BCE. Their Median and Achamenid dynasties held it until Alexander in the late 300s. He was at the farthest fringes of his reach, which is always the weakest part of any empire, but he didn't lose it; he died its ruler, and, despite his lack of interest in planning for what to do with it afterward, his successors held it as a Greek kingdom (Seleucid & Bactrian) for well over 400 years. They finally got knocked loose not by the local natives but by other invaders, the Yuezhi, who ruled it for about 250 years until the Persians took it back for over another 400 years until the Arabian caliphates took over and ruled for at least a couple of centuries before it starts getting slightly more complicated over the following few centuries.
Starting in 819 CE, after almost 1500 years of recorded history without a single day of independence from foreign empires (or a single empire holding it for less than about 250 years before another empire takes it), we finally start seeing the dominant foreign empire of the time, the Abbasid caliphate, getting pushed back from at least part of Afghanistan, both by locals and by other invaders. Afghanistan's own homemade Samanid and Saffarid dynasties (cousins of the Persians but this time at least not
from Persia) managed to keep Kabul and neighboring eastern parts of the land until 1003 while occasionally gaining & losing other chunks of land back & forth against the Arabs and a couple of Turkic tribes (the Ghaznavid and Khwarazmian dynasties). Once the local upstarts were put back down out of the picture again, the Arabs and Turkic tribes kept going back & forth until the mid-1200s, when they both got driven out, not by the people of Afghanistan, but by, once again, yet another successful invading empire, the Mongols.
Khan's successors weren't his own descendants for long because the Mongolian power structure was prone to internal turnover, but his military and political successors kept the military & political entity going under other names like "Timurid empire" without losing Afghanistan or most other nearby territory until well into the 1500s. And who was it that finally chipped enough away at them to get down to the last chip in Afghanistan... oh, look, it's the Persians again, this time under the name "Safavid"...
another foreign rulership over Afghanistan that lasted well over
another 250 years. (The Safavid dynasty ended in 1736 but that was an internal succession with no gain or loss of territory; the usurping Afsharid dynasty of Persia would rule another 60 years after that.) Toward the end of Safavid rule, some territory in Afghanistan was won from them by Pashtuns of the Hotak dynasty, but they only held on for 29 years before Afsharid Persia took it back.
Independence from foreign empires doesn't really begin until the military career of an Afghan named Ahmad Shah Durrani (1722-1772). Afghanistan & Pakistan were on the edges of a few different empires in different directions (Afsharid Iran in the west, a couple of Indian ones in the east & south, and a Mongol-Turkic one in the north), which happened to be weakening and ready to shrink back at about the same time, instead of one weakening & shrinking while another strengthens & expands. This created an opportunity for the border provinces, and Durrani took that opportunity, taking over Afshanistan, Pakistan, and parts of some neighboring countries, especially eastern Iran. The government has changed forms since then and lost some territory (most notably Pakistan and an almost Afghanistan-sized chunk of Iran), but has been the first and only relatively stable continuous entity to rule Afghanistan from the inside instead of the outside since then.
Prior to Durrani, there's
not one single instance of Afghanistan
ever keeping an invader out, completely throwing a conqueror out, or even managing to temporarily take back bits & pieces from a conqueror in less than about 200 years, nevermind putting an invader in a "grave". It's simply spent almost its whole history as a perpetual province of one outside empire after another, typically for hundreds of years at a time, with each one's time ending not when the people of Afghanistan did something to end it, but when the next one came through. The pattern didn't end until those outside empires happened to fade at about the same time anyway without another new one developing to be the next in line.
Next you might think "OK, but what about since then?" After all, of the main three examples the purveyors of this myth most often use, two were pretty recent on that scale. (The third is rather bizarrely Alexander, who can only be said to have been defeated by Afghanistan if you count the country's
germs as defenders of the country, but we'll just ignore that for now.) There were some other conflicts for Afghanistan, such as against the Sikhs, but nobody ever called them a major world power. That leaves us with the British Empire and the USSR.
The Brits meddled in Afghanistan three times: 1839-1842, 1878-1880, and 1919. Even by the earliest of these dates, they were already stretched thin around the world and deciding which places were and weren't worth the trouble. It was 56 years since they'd quit the American war for independence, which is widely regarded as not a defeat so much as an "Eh, why bother", because, although they were significantly more powerful, they had significantly more other lands to deal with too. Their only way to Afghanistan was through India/Pakistan, where they did have a military presence, but just enough to keep them in line and paying taxes, while leaving most of the administrative/ruling work to the locals. Their biggest military priority was to keep the home islands safe during Europe's era of back-&-forth wars that kept happening at the time. And their two 19th-century excursions into Afghanistan lasted less than 3 years apiece and the last one didn't even last a year. Considering all of this together, this does not look like defeat; it looks like another "Eh, why bother".
That leaves the USSR. Even granting this one, 1 isn't much of a historical pattern; it's the lone exception at most, if it's even that. And that's without considering the help Afghanistan got from the USA at the time, or how much effort the USSR really put into it, or the fact that the more we've learned about Russia & the USSR since then the more of a paper tiger they look like for other reasons.
I'll leave it to others, or to another later post of mine, to ponder why a myth so far out of line with reality is nevertheless as accepted as it is here & now...
