I remember some Lt Col giving a presentation where he said that the die-hards are about 10% of insurgents and 90% of the others can be neutralized by, basically, honest and competent government. Sympathizers even more so. That seems to have been a major problem for the US in Vietnam, Iraq and Afghanistan.
What are the most effective ways they can be pro-active or at least appropriately reactive?
Timothy McVeigh killed 168 people. The Beltway snipers killed 17 people. It seems like it would be pretty simple for insurgents to just all do a truck bombing, with one bombing for every 2 insurgents in the cell. Simultaneously so that the authorities can’t take countermeasures or cut off their supply of explosives.
I mention the beltway snipers because they were examples of terrorists who basically turned themselves in. Had they not sent ransom notes and made other major errors - but instead just drove around and kept killing people randomly - their shooting spree could have gone on much longer. Apparently, the authorities didn’t have a shred of evidence and were looking for the wrong vehicle.
Indeed. I’ve always insisted that if you wanted to harm the US government and economy while minimizing casualties you need to blow up a few bridges and one tunnel. Destroying the ways federal workers can get to their jobs and you’ve halfway paralyzed the American governments ability to respond to things for years.
Ditto NYC. Cut off the workers for the financial and media systems from where they can do things and watch the economic disruption spread.
Relatively soft targets that would take real time to repair or rebuild and disruption is maximized while also killing few people. That’s how a group efficiently uses bombings.
They weren’t killing the same people, so it’s hard to compare. Loyalists overwhelmingly killed civilians (85.5%). Republicans killed mostly military/police, with a sizeable civilian victim group (53 and 35). The government killed mostly civilians, with a sizeable Republican death rate (51 and 40).
Who are you counting as “civilians” killed by loyalists? They didn’t have anyone to kill except civilians.
It doesn’t break it down by religious status or anything. They could’ve killed Republican operatives, too but didn’t for reasons unknown to me. It is possible that there is difference in reporting; it’s not like paramilitaries wear badges.
I’m assume you are talking about LTC (now retired) John Nagl. He was one of the lead authors of FM 3-24 when we finally recreated counter-insurgency (COIN) doctrine in 2006. He also became the face of public relations for DOD to explain the new doctrine and why it would make a difference for a while.
It depends. Insurgencies and counter-insurgencies are all affected by multiple factors… and how their opponent chooses to operate within the factors constraining their choices. There was a phrase bouncing through the US Army as we rotated into a COIN focus for Iraq and Afghanistan. COIN was “the graduate level of war.” It would be a big deal to try and summarize a highly complex operational environment in a post or two.
DOD put the effort into summarizing the subjects for me. 
If you really want to delve into it you might check out:
FM 3-24 INSURGENCIES AND COUNTERING INSURGENCIES
FM 3-24.2 TACTICS IN COUNTERINSURGENCY
A couple important notes. DOD issues their own security certificates so the typical checks treat their certificates as invalid. You are likely to get security warnings from those links; I didn’t but probably already allowed the exceptions. More importantly it’s not necessarily easy reading. The Army writing style is supposed to focus on avoiding passive phrasing and keep things relatively simple for those that don’t necessarily have college level of reading skills. For doctrinal manuals it usually does. It can rely heavily on bodies of knowledge that are just assumed to exist in the target audience. though. Acronyms, initialisms, and abbreviations are spelled out the first time they are used. There’s a lot of them though. Pretty quickly it can devolve into a firehose of jargon and acronyms.* US military English is also effectively it’s own dialect. There can be very specific meanings for words and phrases that aren’t clear to someone inexperienced with the dialect. Those differences can have a big effect on meaning. Don’t be afraid to consult the glossary. It might be useful to start with the glossary. Searching for ADP 1-02 and/or ADRP 1-02 can also help if you are struggling with a term that didn’t make the glossary.
Clear as mud, right? 
Generally speaking, both Republican and Loyalist paramilitaries largely refrained from killing or trying to kill the other side (with some exceptions). It was a trick easily repayable in kind. They did feud amongst themselves to some extent, often over control of protection or drugs rackets rather than doctrinal differences. Informers, or suspected ones, were dealt with mercilessly.
Sounds like the bulk of the IRA was self-glorified street gangs. I suppose that would be some of the first people to join and some of the most enthusiastic operators. Someone like David O Connell, an IRA leader, didn’t strike me as a street thug, however. He didn’t give that impression to the UK government either.
So much of economic activity is predicated on economies of scale and network effects that those networks and activity flow pattern they enable can present bottlenecks. If you wanted to do high amplitude of damage quickly, aim for the those necks.
While the FMs are very well placed to give an abstract, high-level view, I’m curious to know what that meant in its practical manifestations with which you might be familiar. Could you contrast not the theoretical underpinnings but how they shaked out in different situations?
Thanks for the links. I’ve been working my way through FMs since my teenage years when I became fluent in English and lost interest in GI Joes (I guess I never really did). Each one sounds like a novel written by and for T-800 Terminators.
I’m currently working my way through Weapon System and Information Warfare by Thomas Rona, a DoD paper about the impact of information technology on warfare. Since it’s from 1976 and it dared to make predictions, it’s interesting to see how they turned out.
Related to this, I guess a lot of the problem for soldiers in COIN is a bit like being at sea in a shark movie. Since one party is usually overwhelmingly strong, the other party has to rely on stealth in various forms, like a sniper or submarine has to. That means that as the stronger, COIN side, you’re usually lacking critical information about threats/opportunities because that’s where the game is played. If you didn’t lack that, you’d be on the way to win already. When getting hit would be fatal, whether we’re talking about nukes, an AsHM for a ship or COIN airstrikes for insurgents, the performance bottleneck for either side is information.