Unfriendly Persuasion

 is a quest in Fallout: New Vegas. This is a quest given by Marcus, the leader of Jacobstown. Four NCR mercenaries and a NPC named Norton are attempting to instigate a fight between them and the Super Mutants and Nightkin living at Jacobstown. Marcus asks the player to deal with the mercenaries peacefully, although the player is given multiple other options in order to deal with the mercenaries in any manner they see fit.

Quick walkthrough
Marcus asks you to convince some NCR mercenaries to go away peacefully. With 65 speech you can simply ask them to leave and complete the quest. If you are Idolized with the NCR you will have an option to use your NCR reputation to convince them to leave.

If you ask them how much it costs to bribe them they will say 2500 caps. You can get the caps from Marcus by asking him. Lie to him and you can get 3000 out of him. If you then use speech to convince them to leave for free you have just earned a mint. Another alternative is to take the money from Marcus, convince them to leave without paying them, keeping the money. Once they start walking away, return to Marcus telling him they are leaving, this ends the quest and you gain XP points. Then, if you return to the mercenaries they should still be slowly walking away. At this point it is wise to save because it could take a few tries. Let them get separated from each other and get spaced apart. Using a Silenced Sniper Rifle with armor piercing rounds, start from the man at the back of the line, crouch down (ensuring Sneak Attack Critical) and take them out one at a time. Do the same for each man up the line, ensuring that the others aren't aware that that man behind him just got his head blown off. During this Sneak Attack, Norton has a tendency of getting way in front, you just have to catch up with him. If you can manage to kill all five of them with one shot each, you can kill all five and not suffer any infamy with the NCR. Once successful, you can loot all five bodies for some serious armor, sniper and plasma rifles.

Alternatively (and more easily, as they're not moving), you can stealth kill all of the mercs, except Norton, one by one before starting the quest with the conversation with Marcus. Work from the back of them, starting initially with the two on the south side of the road, and then the two more closely bunched behind the rock on the north side, taking the rearmost (left) one first. You might need to loot the merc bodies as you kill them one at a time, as the weapons have a tendency to vanish if left too long.

Only Norton needs to be alive to resolve the quest peacefully, so you can then have the conversation with Marcus to start negotiations, convince Norton to leave, return to Marcus to get the XP and Jacobstown status boost, and then return to finish off Norton who is walking down the road with another stealth kill - easier to do as there's now no-one around to see you do it anyway, so no loss of NCR status.

Detailed walkthrough
First after finding Jacobstown, Marcus will approach you with news of New California Republic mercenaries harassing the town. He'll then ask you to peacefully deal with them. When asked why the the mutants don't kill them Marcus says it's to avoid the NCR from having an excuse to terminate Jacobstown.

Finding the mercenaries is relatively easy in that they're directly in front of the town. To resolve the quest you can give them 2500 caps or with a 65 Speech test peacefully tell them to leave. If you have a very high NCR standing you may also be able to tell them that you're an NCR hero, and they'll leave without a speech check or paying them.

A way to get caps and loot but with NCR infamy is to go to Norton (mercenary leader), ask him how much it would cost for them to leave, then go back to Marcus and  to him for Bad Karma and get the 3,000 Caps. Then get in a hidden position (behind them) and take every mercenary out with a silenced weapon, then go to Norton and either convince him to leave (65 Speech), or pay him 2,500 caps. Then head back to Marcus, and tell him you solved it "peacefully". You'll get their loot, (2x Plasma Rifles, 2x Sniper Rifles, Heavy armor, and associated ammo), and the least amount of caps you can recieve is 500.

An alternate way of getting the caps and loot without gaining infamy is to complete the speech task, but then as Norton and the mercenaries are walking away, kill them one at a time while hidden. If the mercenaries bunch up too close to each other, talking to them will stop their walking momentarily.

1. Use a long range suppressed weapon and mines to take them out with sneak attack criticals and explosions (Or just a Silenced Sniper Rifle, head-shot sneak critical will kill them).

2. Take them out head on, Anti-materiel rifle with Armor Piercing rounds recommended.(hardest)

3. Attack them then run to Marcus (make sure he doesn't die, but he has 500HP and 30DT) and the other Super mutant and let them kill the mercenaries. (easiest)

4. Shoot them one after another (headshots or other one-hit-kills) from a position where only the person you're currently killing would be able to see you. It doesn't even have to be a silenced (or scoped, if your manual aim is good enough) weapon; the others will become hostile for a short while, then turn back to friendly/neutral.

5. Before you finish the last chat, fast travel away. Check back periodically. The local Cazadors will kill the mercenaries and you can just loot the bodies. If they kill Norton you can only get the aggressive ending, but if he lives to the last you can still get the peaceful one.

6. Prior to talking to Norton, use a silenced weapon to kill the four unnamed mercenaries for exp and their gear. Then, talk to Norton and resolve the issue peacefully however you wish. DO NOT kill Norton, let him walk away (you can also pickpocket him and get a little info on the reason for them attacking Jacobstown), then return to Marcus to claim your reward for 'peacefully' resolving the issue.

After completing the quest you get 250 XP.

Glitch:

 * If the quest is resolved peacefully the mercenaries may be found a few minutes outside Jacobstown stuck inside the Polygon mesh.

Bugs

 * Killing the mercenaries after taking money from Marcus may stop the player from turning in the quest.
 * Not sure why, but paying off the mercenaries while Cass was with me caused her quest chain to fail. At this point with her, I had already gotten the note from the Caravan, but not from the Van Graff's. Didn't try to repeat the issue.
 * After convincing Norton to walk away via caps, later return to the area just south of Silver Peak Mine shows a non-hostile npc on the compass. the spot the compass points points to shows an option to talk to Norton and one or more mercenaries. Doing so does not activate a dialog. (Xbox)
 * Quest was automatically completed (Also - with the quests I currently had active - 'Guess who I saw Today') after updating to 1.2.0.314. ALL the journal entries/directives were checked off as being completed, which I'm not sure is possible given the 2 choices are to either 'come to a peaceful arrangement, or 'wipe the mercenaries out'.