No - that is an assumption and a flawed one. Here's the question for you to ponder - Iran claims no part of Pakistan, so what would these individuals fight the Pakistani State for? The Shia are a minority in Pakistan, and the Shia know this - as someone from a Shia family, I can tell you that NOWHERE has there ever been any kind of discussion about 'taking over Pakistan and implementing Shia Shariah'. Why should the Shia even want that? The law in Pakistan allows the Shia to deal with their affairs per Islamic Shia jurisprudence. The Shia have numerous top level positions in government, the military, bureaucracy, business etc. What do Pakistani Shia have to gain from fighting the Pakistani State? The Pakistani Shia have everything they need to build their lives and prosper in Pakistan. Even with all the noise the Liberandus make about 'Shia genocide', I (being from a Shia family even if I don't identify as a Shia) and many other fellow Shia are the first ones to abuse these Liberandus over their BS. It's stuff like what we've seen recently on this forum, where all Shia are attacked, vile claims are made about their beliefs and practices and their patriotism questioned that really pisses us off.
My dad was a katar Shia, hails from a (still) katar Shia region in Punjab. My mom (Sunni) had to make him back off from some of the more gruesome practices during Muharram (she emotionally blackmailed him using us kids). I have never met a more patriotic Pakistani in my life than my dad. He is the one man responsible for my own patriotic drive and love for Pakistan. Yes, he respected the Ayatollah and respected Iran, but he was a Pakistani first. Don't mistake respect with loyalty. There is no question which side a majority of Shia will fight if it comes to a war between Iran and Pakistan, but questioning Shia beliefs, questioning Shia loyalty is going to do nothing but create friction in Pakistan. How do you think the Indian Muslims feel currently, having their patriotism and loyalty questioned day in and day out?
One thing you have to remember - these conflicts that they are being recruited for (and they are a very small minority of the estimated 20% Shia in Pakistan) are sectarian conflicts that are ongoing. So long as we don't have a sectarian war/conflict in Pakistan, Pakistani Shia will not take up arms domestically, on behalf of ANYONE. If they do take up arms, it will be against the groups targeting them in a sectarian conflict. Pakistani Shia have stayed loyal despite the Shia Hazara being targeted repeatedly, despite the days in which the Laskhar-e-Jhangvi/ SSP were on the rise. Attacks were limited to the members and leaders of the respective groups. Never once did the Shia take up arms against the Pakistani State.
So look at the history of Shia armed movements in Pakistan, who those movements targeted, and rest assured that Pakistani Shia are as loyal and patriotic to Pakistan as anyone else.
One final note to the members that keep asking why the Shia still respect Iran - most Shia simply do not see Iran as a threat to Pakistan. They just don't because most Pakistanis (Shia & Sunni) simply don't see anything in the media about Iran carrying out terrorism in Pakistan (no one outside of people like us on the forum have really dug deep into Yadav and what his links were and how Iran may have facilitated him). Look at the global opinion polls about Iran - anywhere from 50% to 70% of Pakistanis view Iran favorably. Those are not all Shia. So trying to use a favorable view of Iran as a yardstick for patriotism or loyalty is absurd since that would mean that half the population of the country is unpatriotic and disloyal.