For the BFA War Campaign, there are 4 breadcrumb quests: Operation: Blood Arrow, Operation: Cutpurse, Operation: Gryphon's Claw & Operation: Heartstrike. They all act in the same way. Originally they would pop up during the campaign, telling you you needed to get more reputation with The 7th Legion before opening up next step. However, in 8.2.5, Blizzard removed the reputation requirements for the War Campaign quests. At first I thought that had effectively made these breadcrumbs unavailable, but they can be done, you just have to do things in a very specific manner.
For Operation: Blood Arrow:
1) Do all the intro quests from Halford, up to and including Blood on the Sand.
2) Do not accept next War Campaign quest from Halford yet.
3) If needed, grind 7th Legion reputation up to Friendly 4500/6000. Check https://www.wowhead.com/guide/the-7th-legion-reputation-guide-6196 for tips.
4) Triggering the actual quest can be done in two ways: Getting reputation with 7th Legion past the required rep (for example by doing a WQ on Zandalar) or by relogging in Stormwind.
5) Now you can turn in Operation: Blood Arrow and continue on with next step of the War Campaign.
For Operation: Cutpurse:
1) Continue on with War Campaign, up to and including Target: Blood Prince Dreven.
2) Do not accept next War Campaign quest from Halford yet.
3) If needed, grind 7th Legion reputation up to Honored 3000/12000.
4) Triggering the actual quest can be done in two ways: Getting reputation with 7th Legion past the required rep (for example by doing a WQ on Zandalar) or by relogging in Stormwind.
5) Now you can turn in Operation: Cutpurse and continue on with next step of the War Campaign.
For Operation: Gryphon's Claw:
1) Continue on with War Campaign, up to and including Gallywix Got Away.
2) Do not accept next War Campaign quest from Halford yet.
3) If needed, grind 7th Legion reputation up to Honored 7500/12000.
4) Triggering the actual quest can be done in two ways: Getting reputation with 7th Legion past the required rep (for example by doing a WQ on Zandalar) or by relogging in Stormwind.
5) Now you can turn in Operation: Gryphon's Claw and continue on with next step of the War Campaign.
For Operation: Heartstrike:
1) Continue on with War Campaign, up to and including A Clean Escape.
2) Do not accept next War Campaign quest from Halford yet.
3) If needed, grind 7th Legion reputation up to Revered.
4) Triggering the actual quest can be done in two ways: Getting reputation with 7th Legion past the required rep (for example by doing a WQ on Zandalar) or by relogging in Stormwind.
5) Now you can turn in Operation: Heartstrike and continue on with next step of the War Campaign.