There is no going back. Nor should we want to. Conquest means killing people: killing them for access to resources, markets and slave labour.
When we pulled back from Empire (and America moved in) we left behind friendly regimes that would 'play ball' with the Bank of England and big business. This is one of the reasons for much of the instability in the Middle East. They've finally gotten round to getting rid of those regimes.
Moreover, next time you see a map of the Middle East - pay attention - you'll see unaturally straight lines all over the place. Those lines were drawn by the likes of Lord Mountbatten: the last Viceroy. This wasn't done for the benefit of the locals.
You might also spot a country called Israel. We foisted that one upon them as well.
Build up a 'new' empire? We have yet to pay the full price for the old one.
And what was it, exactly, that we - the ordinary working people of Great Britain - got out of the old empire? Oh yes; at its height: during Victoria's reign, we did have full employment - or should I say 'poverty in work' - with pittance wages, children working twelve hour days along with child prostitutes thronging the streets of London, as the old were thrown into the workhouse.
Oh for those good old days, the British Way and a pair of rose-tinted-spectacles.