True. Section 8 is powers of Congress, and Section 9 limits powers of Congress. Since Section 9 is asserting what shan't be done, it naturally doesn't express directly who can do it. One would suppose however, that it is pointless to tell an entity that is powerless anyway, the limits of its power.
... until the Supreme Court weighs in on the matter the issue of just who may suspend it remains unsettled.
In the universe of possibilities, the question is slightly unsettled; but SCOTUS in Milligan described the Constitutional parameters. The power falls to Congress, unless temporary suspension is required due to impossibility of Congress to weigh in.
We have confined ourselves to the question of power. It was for Congress to determine the question of expediency. And Congress did determine it. That body did not see fit to authorize trials by military commission in Indiana, but by the strongest implication prohibited them. With that prohibition we are satisfied, and should have remained silent if the answers to the questions certified had been put on that ground, without denial of the existence of a power which we believe to be constitutional and important to the public safety,-a denial which, as we have already suggested, seems to draw in question the power of Congress to protect from prosecution the members of military commissions who acted in obedience to their superior officers, and whose action, whether warranted by law or not, was approved by that upright and patriotic President under whose administration the Republic was rescued from threatened destruction.We have thus far said little of martial law, nor do we propose to say much. What we have already said sufficiently indicates our opinion that there is no law for the government of the citizens, the armies or the navy of the United States, within American jurisdiction, which is not contained in or derived from the Constitution. And wherever our army or navy may go beyond our territorial limits, neither can go beyond the authority of the President or the legislation of Congress.
There are under the Constitution three kinds of military jurisdiction: one to be exercised both in peace and war; another to be exercised in time of foreign war without the boundaries of the United States, or in time of rebellion and civil war within states or districts occupied by rebels treated [71 U.S. 2, 142] as belligerents; and a third to be exercised in time of invasion or insurrection within the limits of the United States, or during rebellion within the limits of states maintaining adhesion to the National Government, when the public danger requires its exercise. The first of these may be called jurisdiction under MILITARY LAW, and is found in acts of Congress prescribing rules and articles of war, or otherwise providing for the government of the national forces; the second may be distinguished as MILITARY GOVERNMENT, superseding, as far as may be deemed expedient, the local law, and exercised by the military commander under the direction of the President, with the express or implied sanction of Congress; while the third may be denominated MARTIAL LAW PROPER, and is called into action by Congress, or temporarily, when the action of Congress cannot be invited, and in the case of justifying or excusing peril, by the President, in times of insurrection or invasion, or of civil or foreign war, within districts or localities where ordinary law no longer adequately secures public safety and private rights.
We think that the power of Congress, in such times and in such localities, to authorize trials for crimes against the security and safety of the national forces, may be derived from its constitutional authority to raise and support armies and to declare war, if not from its constitutional authority to provide for governing the national forces.
We have no apprehension that this power, under our American system of government, in which all official authority is derived from the people, and exercised under direct responsibility to the people, is more likely to be abused than the power to regulate commerce, or the power to borrow money. And we are unwilling to give our assent by silence to expressions of opinion which seem to us calculated, though not intended, to cripple the constitutional powers of the government, and to augment the public dangers in times of invasion and rebellion.
It placed restrictions on where it can be suspended, not who can suspend it. It addressed Congress in the case because habeas corpus had been suspended under powers granted by an act of Congress. The Supreme Court has never ruled on just who may suspend it because the matter has never been taken before the entire court. It should have been, in 1861, but it wasn't. The matter remains unresolved.