I am to understand that the president would need congress to allow such an attack, and that means congress would need to officially vote on it. And isn't congress completely transparent, thus any voting on the law would be quickly found out by the enemy through means of the Internet?
For example, let's pretend President Obama found out through spies that North Korea had just secretly developed a futuristic long range nuclear missile that could easily evade defense mechanisms and hit the United States.The only way to be able to stop N. Korea without them launching their missile in retaliation would be to launch a huge full scale surprise invasion. Obama knows that if they found out about plans of such an attack, they would launch their missile. Could President Obama be able to launch a surprise attack such as the one mentioned while still following the rules of the constitution? Could he somehow get a closed door congress vote and secretly declare war?
Edit: Grammer
Edit 2: I'm not asking if a surprise attack could be done, but rather if the such an attack would be following the rules layed out for the Government. Presidents in the past have always had a disregard for the rules given them, especially when it comes to war. I'm more interested in what the constitution does and doesn't allow rather than if the president could carry out a surprise attack without someone stopping him.
Actually, Congressional votes do not necessarily have to be public. The Constitution only specifies that "Each House shall keep a Journal of its Proceedings, and from time to time publish the same, excepting such Parts as may in their Judgment require Secrecy" - meaning they can close the actual sessions off from outsiders, and even omit parts of their journals from publication. Taking the Constitution up on that permission, the Senate met in secret until 1794, and both houses have occasionally done so since.
In practice, as /u/penguin_says_slide explains, a President is unlikely to get Congressional approval for a secret attack. However, should he choose to do so, Congress could definitely vote their assent in secret.
this is really a us political science question. but i'd imagine the answer would be probably given that the war powers resolution has been around since vietnam. something like an eminent nuclear strike on us soil would certainly be appropriate for the president to use the war powers resolution and launch a pre-emptive strike.
the more interesting question though is if the war powers resolution is actually constitutional - no one's ever tested its constitutionality. and because congress itself passed the law and asserts its necessity (through the necessary and proper clause in the constitution), it's hard to figure out how anyone could challenge it in the supreme court since they wouldn't have standing. congress can certainly repeal it if they so desire, but until they do, it's been law for many a decade and i don't see how the supreme court would ever be in a position to strike it down. you could make a very strong argument that the wpr really isn't constitutional, but well it's not really relevant what we think.