An unofficial, very unreliable and seemingly paranoid source advised me that if I go to Pakistan then my subsequent international immigration procedures will become complicated due to security concerns.

Would a visit to Karachi, Pakistan -- in the context of a year with a RTW (AONE4) ticket along with several international trips aside from and included in the AONE4 (Bangladesh, Nepal, India, Hong Kong, UAE, S. Korea, England, S. Africa, Poland, Italy, etc) -- set some sort of flag in the immigration database that could make my subsequent int'l travel less smooth?

I'd really like to go visit a friend in Karachi, but don't want to create immigration problems for myself. I am a US citizen. I have quit my job to do this travel. (Might not being employed be another possibility for alert???)

Maybe, but I wouldn't let that stop me from going. After I visited Lahore a couple of years ago I had a couple of minor issues with immigration in the next month due to having been in Pakistan. No references since.

I had a harder time entering USA last year on a RTW that included visits (before reaching USA) to such places as Iran, Iraq, Libya. However subsequent visits to USA have had no issues.

My Pakistan visa was on a piece of paper very lightly stuck into my passport, that subsequently fell out a month later. IMHO you are being too paranoid.

It won't cause much serious issue. The most likely issue will be some US airline-retained security contractor asks more questions about why you went somewhere and what you did there. Hundreds of thousands of US citizens visit Pakistan every year or two and then travel the world with no more issue than they would have if not having gone to Pakistan.

"Why did you go to Pakistan?"

"For the same resident the President of the United States went there before becoming President."

On the actual RTW yes you will get questions from most countries (USA, UK, Australia etc). This is because immigration will be able to see your entire itinerary. You might get a few delays, but wouldn't let it stop you. Just be honest.

I had a Pakistan visa in my passport for quite a while from my visit in 2006 (new p/p now), and never really had too many problems. A few questions here and there. I also had Iran in there as well come to think of it.

It's a big country and MANY people go there, so don't worry about it.

Having said all that, my former employer MADE me get a new passport in late 2007 because of my Iran and Pakistan stamps (didn't want me to get refused entry on my various work trips to USA, and said if I did, I'd have to foot the bill for the ticket if I was refused.... ). So your paranoia is quite common it would seem.

Thank you all for your quick and re-assuring feedback.

I went to Karachi last year on a RTW and had no subsequent problems or even inquiries. I went there without a prearranged visa, though (very long story), and had a few problems on arrival.

It all worked out in the end.

There may be a difference in impact if you are vs aren't a US citizen. As a non-US citizen, there was clear impact. I had secondary screening on the majority of my trips to the US after a trip to Pakistan. Added ~30 mins to getting through immigration, and I'm pretty sure I got the full baggage screening from customs once or twice just for this reason too. It stopped about a year later.

Yes, that's true - good point. Now that I think about it, they did ask me about Pakistan on another entry several months later. Ironically, it was when I was coming back from vacation - strange since I often come back from places like Pakistan, Iraq, West Africa, etc. and am rarely questioned then!

It's hit and miss in my experience (non-US citizens arriving in USA with previous visits to certain countries). Having said that I now try to visit USA before those other places on RTW trips (annoying because the schedules work much better for me in the reverse direction).