Iran - Royal Navy detainees

This situation with the Royal Navy detainees in Iran seems quite perplexing. We say that our naval personnel were in Iraqi waters, yet the Iranians state that they were in Iranian waters. Besides, is taking them as hostages really necessary or prudent? Wouldn't it be more fitting to merely warn them that they were in Iranian waters and ask them to leave immediately?

Some idiots have stated that we "declare war" against Iran, nonetheless the solution seems fairly simple to me.

In future, we should refrain from engaging in "UN mandated" missions. This situation with the Iranians is simply a consequence of Blair's interventionist foreign policy. If the Royal Navy were solely protecting British waters and British citizens, then it wouldn't have to interfere in foreign skirmishes that don't undermine British sovereignty. If anything, we should leave the UN. Would we lose "influence" in the world? Why would we? What is the inherent good in "global influence" anyhow? The UK would still have one of the largest economies in the world and people from overseas would still desire to trade with us. As for the seat on the Security Council, well so what? Again, the concept of having influence in the world seems rather narcissistic to me. It's just a means of saying "my country is important" or "my country is better than your country". It's really an infantile, playground mentality. I would only want Britain to be a peaceful, secure, prosperous and free country. Global influence is secondary to such a principle.

In a market anarchist/voluntaryist society, individuals should be free as to whether they want to engage in humanitarian efforts. If individuals want to help the Iraqis, then they should be free to do so. In that sense, governmental force would not be needed (to tax us and then spend it on the armed forces) to patrol foreign hotspots.