We're joined now live from Singapore by Melina Nathan, Associate Research Fellow at the Institute of Defence and Strategic Studies.

Welcome to the programme. This is the latest in a long line of squabbles that have marred relations, isn't it? Why do Singapore and Malaysia find it so hard to get on?

Melina Nathan: Well, I think from the point of view of Singapore, always at issue is a sense that Singapore's sovereignty is something that's treated with a kind of disregard by Malaysia when it suits its purposes.

And from the point of view of Malaysia, I think whenever it is experiencing domestic political difficulties, Singapore becomes a successful target.

So if you look at the deterioration of bilateral relations, it reached a peak or spike in 1998 when Malaysia was really affected adversely by the Asian financial crisis and when you had the kind of political fallout between Prime Minister Mahathir and his protege Anwar Ibrahim and Singapore then became, I think, quite a convenient outlet.

From the point of view of Malaysia, I think there is the sense that, you know, Singapore gets a bit too big for its boots, that it's insensitive to sensitivities in Malaysia and at issue really is the fact that both states, whilst so similar in terms of history and culture and even demographics although, you know, in reverse, in reverse order as it were, have chosen quite different developmental paths and at a point where Malaysia seems to be suffering economically and Singapore's doing well, I think the comparisons become quite invidious.

Tim Luard: And is it just hot air or are these arguments actually preventing long-term neighbourly cooperation? There are things like water supplies, aren't there?

Melina Nathan: Absolutely. Well, I think this brings up an interesting point. The Singapore Prime Minister Goh Chok Tong has actually said that Singapore chooses economic interdependence, chooses to be dependent on Malaysia where water's concerned because in a sense, this shows it has a stake in long-term relations with its neighbour, and of course both countries are heavily economically interdependent on each other.

But the point where economic independence is concerned of course is that there is an issue of trust and either side can then accuse the other of trying to use leverage or trying to benefit more than the other party in this kind of relationship.

As to whether this is just hot air or not, I think what we can agree upon is the fact that there have been ups and downs in this bilateral relationship ever since independence in 1965 and one assumes that this pattern will continue until you arrive at a situation where, you know, Malaysia is experiencing a degree of prosperity and it can therefore afford to look on Singapore with greater detachment.

Tim Luard: Okay. Melina Nathan, thanks very much for joining us there live from Singapore. Of course, Lee Kuan Yew always wanted to run both places.