Drafted during the years 1776 and 1777, while the colonists were still fighting for independence, the Articles of Confederation created a weak national government with most of the governmental powers retained by the states.
The Articles provided no separation of branches. There was no president or any other independent executive, nor was there a federal judicial branch. Congress, the legislature, was the only branch of government. Laws required unanimous votes. Members elected to congress did not vote as individuals, but as states. While congress did have some powers, it could not enforce its laws on the states or the people. States were permitted to coin their own money. There was no regulation of commerce between the states and states could even enter into treaties with foreign nations and declare war, with the consent of Congress. Congress could not tax the states or the people, it could only request funds to run the government.
I've bolded the main reasons why the AoC is a total failure...
States could enter into treaties or declare war
with the consent of Congress. There is nothing wrong with States being able to coin their own money. A major problem today is the Fed's monopoly on the currency which is nationalized. Congress didn't need to be able to enforce laws on the states, and we've seen how terrible in the practice the notion of security for liberty is. Trying to protect individuals by centrally taking away their liberty is stupid, and even if that's possible, some people don't consent to it. The states could protect their people by taking away their liberty. We see how that failed in MA--the high taxes resulted in Shay's Rebellion.
There is also nothing wrong with Congress voting as States. Some people, myself included think that's a lot better.
Also, this country was founded as free and independent states, so when assembled they should control the executive power. The commander in chief, treasury secretary, and state secretary (diplomats, census, etc) shouldn't be independent of the united States assembled. Having a unitary executive sucks, and we've seen how that's worked out with Lincoln and every President starting with FDR.
Execution of enumerated powers of the united States Assembled didn't require unanimous votes they only required 9/13 of the States. That's the way it should be, and requiring unanimous consent from the member states to change the country's supreme law is the way it should be. Why should 3/4 of the States subsidize all of them?
As for the centralized power to tax individuals, that hasn't worked out well because that criminalizes people. The Whiskey Rebellion and Fries' Rebellion both happened the first full decade the Federal Constitution was in effect.
Having a centralized power to tax doesn't make any sense when you can borrow. If government exists, then there should only be the power to tax or to borrow, but not both. Deficits of the union went up more from 1791-1795 vs 1784-1788.
The reason why there was no power to tax under the AoC was because a few states rejected a 5% tariff to pay off the debts from the Revolution. They rejected it because they were worried that it would fund a civil service bureaucracy. Hamilton proved them right when he became Federal Treasury Secretary. The Federalists (the people pushing for the Federal Constitution) had no intention of paying off the debts with taxation, as the pro-Federal Washington Admin proved when it just got the union further in debt.
Finally, there was no need to tax under the Articles of Confederation because they could've distributed the debt to the States based upon population. The reason why that never happened was because the Federalists and speculator class campaigned against doing that. The speculator class saw that they would benefit from centralization of power(
http://mises.org/daily/1296).