Moving from the government sector (tax) to finance?

Background: I’m an international undergraduate going to study at an Ivy this fall. I’m also on scholarship from my country’s government After I graduate, I’m required to return home and spend 5 years working in the government, specifically in the field of Tax.

However, for the last year I think I’ve really developed a solid interest in IB/consulting. I taught myself how to build DCF models from scratch and fuelled my interest by reading a ton of books about the finance industry in my free time.

Here comes the problem: I had no choice but to take a government scholarship as I couldn’t have otherwise financed my university education. But it also means I could be stuck working in a bureaucratic job or career that I might not like (emphasis on might) for a good few years, rather than trying my hand at finance.

Now, I’m trying to figure out potential opportunities to break into finance at a later stage (JUST IN CASE my government stint in Tax doesn’t work out). In college, I will definitely be aiming for finance internships in my summers, to show a prospective future employer that I would at least have some experience and know what I’m trying to break into. However, I’ll have to go into these internships knowing there’s zero chance of me accepting any offer to join the firm after graduation because of my obligations to my country.

My situation poses questions that I cannot find answers to online:

If I had a good few years of regulatory experience in the government in Tax (with a couple of undergrad internships and a degree from a target school), what kind of finance-related jobs could I even be recruited for? Would some division of a large IB/PE/Consultancy/Big 4 firm even have a relevant place for me? (I know there are Tax divisions in many firms but would they take in someone previously from the very-bureaucratic government?) Or will I have to start over as a 30 year old analyst?

Additionally, what kind of skills would I need to develop in my government job or in my own time to prove I’m capable of making the switch to finance? How about going for an MBA before that?

Or, have I doomed my ambitions of working in finance permanently by joining the government?