Sanctuary and Compel Hostility

[Finlanderboy]

If I have both of these spells activated and the monster fails it's will saves while I follow it around what does it do?

Whenever a creature you can see that threatens you makes an attack against one of your allies, as an immediate action, you can compel that creature to attack you instead. When you compel a creature to attack you, you must first overcome that creature's spell resistance, and the creature can attempt a Will saving throw to ignore the compulsion.

Any opponent attempting to directly attack the warded creature, even with a targeted spell, must attempt a Will save. If the save succeeds, the opponent can attack normally and is unaffected by that casting of the spell. If the save fails, the opponent can't follow through with the attack, that part of its action is lost, and it can't directly attack the warded creature for the duration of the spell. Those not attempting to attack the subject remain unaffected. This spell does not prevent the warded creature from being attacked or affected by area of effect spells. The subject cannot attack without breaking the spell but may use nonattack spells or otherwise act.

[King of Vrock]

Using compel hostility is using an attack spell. Any spell that would break invisibility, such as spells forcing a saving throw are attack spells. So this combo would negate your sanctuary.

--Schoolhouse Vrock

[Finlanderboy]

if you had the compel hostility cast and then santuary afterward the immediate action of causing it to attack you counts as an attack?

[Starglim]

Finlanderboy wrote:

if you had the compel hostility cast and then santuary afterward the immediate action of causing it to attack you counts as an attack?

Since you're directing the spell in such a way that a fresh target must make a Will save against an unfavourable effect, I think this follows.