Sorry, I’m inspired by the wedding of Prince William and Princess Catherine Middleton. I would dearly have loved to have been a part of it. So, here are several ways by which Singapore can rejoin the British Empire.
The Classification of British Imperial Rule
The overseas territories of the British have three different classifications:

Colonies were those areas directly ruled by a governor on behalf of the British government and representing the Crown. The governor was responsible to the Colonial Office in London, although he usually had wide powers of discretion. These were the most common form of imperial control. (E.g. Pre-1997 Hong Kong)
Protectorates were territories where the local rulers could continue ruling domestically but they had ceded the foreign and defence aspects of their government to the British. In return, the British respected and were prepared to defend the ruler from foreign or internal threats. (E.g.Falklands)

Dominions were those colonies that were granted significant freedom to rule themselves. The settler colonies were afforded this freedom. Dominions were fully independent countries after the 1931 Statute of Westminster, although their Head of State continued to be the British sovereign. (E.g. Australia. New Zealand and Canada)
I shall develop the changes to be adopted based on how drastic they are.
Becoming a British Dominion
Let’s consider the least drastic change. Singapore could become a British dominion. We would still be an independent country, like Australia, New Zealand, Canada, etc except that our Head of State will no longer be the President but the Queen of England instead.

Here is a relatively simple consideration. We pay an exorbidant amount of money to our SM, MM and President to perform what seems to be merely ceremonal functions (entertaining foreign dignitries, commission our army, and other ceremonies), and to give advice to the government. I do not see why we cannot simply just abolish all three offices, and we pay the British monarch 50% of their combined salaries as a token sum for them to appoint a Governor General in Singapore to represent the Queen here and perform all the functions of the Head of State and all other related ceremonies.

Not only does this save good money, but it is also a tribute to what unifies us Singaporeans together, our common English language, and our common British heritage, regardless of our many and diverse ancestral origins, it is the British who laid the foundations for Singapore and made it what it is (later Singaporeans would have to build on that foundation), and making our Queen our Head of State is a tribute to their work for Singapore.
Protectorate Scheme (Minor)
We might want to consider instead becoming a Protectorate, whereby Singaporeans will continue to be in charge of all domestic affairs, but we’ll cede all foreign related affairs, i.e. our foreign relations and military, to the British, inclusive of all the changes cited under the dominion scheme. Now, the first thing most Singaporeans will go is to repeat that mantra drilled into us that the British failed to protect us during WWII.

However, let us honestly ask ourselves, if the British were not around to protect us from the Japanese, what’s the alternative? Us against the Japanese?! I challenge any male Singaporean who has gone through NS, to ask if they truly believe that our military is capable of stopping a power such as the Japanese, with their advanced technology, their almost insane patriotic zeal, and their tactical brilliance.
The fact is that the if there is a power which the British cannot protect us from, then it is HIGHLY unlikely that we would succeed as well. But, the average case is that we just need Britain to protect us from our standard neighbours *hint hint*, and there is not a shred of doubt that this they will be able to perform most admirably. As in the case of the Falkland Islands, a British protectorate in South America who was invaded by the Argentinians during 1982, we got this,

So, against our more, erm, petty foes, the military might of the British would do most adequately.

Secondly, we already spend a whooping 20% of our GDP on National Defense. 20%! This is simply outrageous, besides being totally pointless. Let’s face facts: Singapore cannot reasonably hope to win any war which might break out between us and our neighbours. Why? The reason is simple. We might have the greatest weapons, the most advanced technology, the best trained soliders, but the fact is still that we do not produce any of our essential supplies. The minute our neighbour cuts off our supplies of water, fuel and food, we’re doomed. We cannot survive a protracted war. And if we strike them first, and if they are smart, they will practice scorched earth policies, and we’ll still be screwed. And of course, 21st century warfare is no longer about army to army clashes, it is about guerilla warfare, (see Iraq and Afganistan). We do not have the essential supplies and resources to attempt to occupy such an area with them engaging in such tactics. We will not win any war by ourselves.
But if what I heard is correct, that our mission in any war is not to win but to hold out long enough for a Western power to save us and resupply us… then, well. I think that pretty much settles it. Why go one whole big circle, when we ultimately are still dependent on them? Thus, I propose the abolishment of the SAF, and we pay the British government, say, 10-15% of our GDP to defend us? We save money and we get to ride on the deterrent pluses which would come from riding on name of the British royal army.
Protectorate Scheme (Major)
This scheme will include all the changes proposed above, in addition to providing a constitutional role to the British monarch.
I wish to propose that the British monarch shall have independent control over our judiciary, and the Sovereign’s official role over Singapore will be as Guardian of our Constitution and Laws. After all, when Queen Elizabeth II was crowned, her coronation oath included the following,
Archbishop: Will you solemnly promise and swear to govern the Peoples of the United Kingdom of Great Britain and Northern Ireland, Canada, Australia, New Zealand, …and of your Possessions and other Territories to any of them belonging or pertaining, according to their respective laws and customs?
Queen: I solemnly promise so to do.
Even British national anthem “God save the Queen” includes the line of
Long may she reign
May she defend our laws
And ever give us cause
To sing with heart and voice
God save the Queen
Philosophically speaking, the Monarch is the incarnation of the Reason behind our Laws and History. As Winston Churchill puts it,
Above the ebb and flow of party strife, the rise and fall of ministries, and individuals, the changes of public opinion or public fortune, the British Monarchy presides, ancient, calm and supreme within its function, over all the treasures that have been saved from the past and all the glories we write in the annals of our country.
As such, the judiciary must be above and beyond party political interests that they might properly enforce and protect our laws and constitution. In practical terms, this is what I propose.
A body of six or eight judges known as the Law Lords will replace our Supreme Court as the highest court of appeal. They will consist of Singaporeans, but they will be appointed solely by the Sovereign in Britain from amongst the lower judges, and they are answerable only to the Sovereign. This will ensure the independence of the judiciary from party political interests.

From amongst the permanent secretaries of the civil service, the Sovereign will appoint a Governor-General, who will represent the Sovereign in Singapore. The GG will handle all the ceremonial and administrative functions of the British relations to Singapore, including the foreign affairs and the military, which the GG can appoint Secretaries for each office. The GG’s office will run for four years which will then be subjected to a review by the Sovereign, renewable twice, as it may please the Sovereign, which otherwise the Sovereign will simply dismiss the incumbent and appoint another.
The Law Lords and the GG together will review all the laws passed by parliament, and they have the power to conditionally veto any law which they deem to be “unconstitutional”, by a simple majority of voting by the Law Lords and GG, with each Law Lord having one vote and the GG having two. The law will then return back to parliament, which, if it passes with a 3/4 majority, will automatically become law. Anything less and it will be vetoed. However the Law Lords and the GG will have absolute veto powers over any proposed constitutional amendment by Parliament.
The Governor General will have one additional responsibility. Though the GG may not interfere in the functioning of Parliament or the Cabinet, however, he has the power to hold them to account by being able to set up Royal Commissions. The GG can set up a Royal Commission to study any ministry, policy or project of the government and retrieve any information from them which the GG believes to be in the interest of Singaporeans to know. (A power which our current President is suppose to have when the last President requested the financial accounts of our government) If the government fails to comply, the GG can take them to court to force them to hand over the required information. Any official commission will then have the results published in the press for the information of the citizens. Thus, the GG will keep the government accountable to the people. The GG can also receive any petition directly from citizens to invoke a Royal Commission.
Conclusion
Ultimately, I see no reason why these proposals should be rejected off hand, as they make eminent sense, including a substantial financial saving and making Singapore a part of a larger history, ultimately, to the providential rule over history of God himself.
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