I think American action will be limited to degrading Iran's air defence capabilities. Nothing more is expected.
Pakistan does not get any benefit in this affair.
No invasion.
Indicators have turned since yesterday.
A strike on Iran by US is very close now. It will be a token strike, no invasion. But main thing is response of Iran.
https://www.zerohedge.com/news/2019-05-20/iran-media-says-uranium-enrichment-quadrupled-pace-weapons-grade-levels
Iran Says Uranium Enrichment Quadrupled, On Pace For Weapons-Grade Levels