1. In the last decade, the politics have definitely shifted to being more anti-immigration than they used to be. For example, it takes at least 6 years to qualify for UK citizenship. This is 5 years to qualify to ILR (Indefinite Leave to Remain) and a year of ILR to qualify for citizenship. This used to be 4 years to get ILR (prior to ~2006?).
2. Adding of extra requirements like Living in the UK test and a nebulous "good character" test.
3. Uncertainty over Brexit. It's far from clear what UK citizenship will get you post-Brexit, if Brexit even happens. Given the rise of the Brexit party and the Tories tearing themselves apart with May resigning and a hard Brexiteer like Boris Johnson likely to be the next PM, a hard Brexit has become much more likely. This may also negatively impact the UK economy.
- What is your earning potential in the US?
- What is your earning potential in [other country]?
- How many years on your current immigration status can you remain in the US?
Context: I'm Australian. I now live and work in the US because the earning potential for a software engineer here is 5x what it is in Australia. As long as you're spending less than you earn you can pack many years of saving into the US in a short period of time so it's worth considering a longer stay even if it is still temporary.
Citizenship:
- What is your current country or countries of citizenship?
- Is your plan to become a citizen of [other country]?
- Do you want to retain your existing citizenship(s)?
- What is your time frame for wanting to gain citizenship?
Some examples:
- You can get Irish citizenship in 4-5 years (IIRC) and can retain your existing citizenship
- Austrian, German and Dutch citizenship (again, IIRC) require you to renounce your existing citizenship to become a citizenship (there are exceptions).
- If your goal is to get EU citizenship because that comes with a lot of benefits like being able to live and work in 27 (or 26 after Brexit) countries.
These are the options I would consider and the reasons why:
1. Ireland. EU citizenship in a relatively short period of time. English-speaking, developed economy and employment opportunities. Also, the country is relatively welcoming to immigration.
2. Canada. This can effectively prolong your stay in the US forever. After gaining Canadian citizenship you can essentially work forever in the US on TN visas.
3. Australia. Relatively easy to get immigration status as a software engineer with a college degree who speaks, reads and writes English (there's a point system). I believe the time frames are relatively short and this too will open up the ability to work in the US via the E3 visa.
There are other factors that come into play too like family situations, long term plans, where you plan to retire, etc.