Editor's note: Rand Paul, a Republican, is a U.S. senator from Kentucky. He will be a guest tonight on Erin Burnett Out Front at 7 p.m. ET.
(CNN) -- This week, I will campaign for Gov. Mitt Romney. I believe this election will and should be about moving America back from the edge of the abyss on which we stand, where our debt and spending threaten to overwhelm and drown us. Romney's belief in free markets, limited government and trade make him the clear choice to lead our country come January.
I do not, however, support a call for intervention in Syria. And, if such intervention were being contemplated, it is absolutely necessary that Congress give any such authority to the president. No president, Republican or Democrat, has the unilateral power to take our nation to war without the authority of the legislature.
At times, I have been encouraged by Romney's foreign policy. I agree with his call to end the war in Afghanistan sooner rather than later and with his skepticism of, and call for reform in, foreign aid, but I am a bit dismayed by his foreign policy speech Monday, titled "Mantle of Leadership."
Romney chose to criticize President Obama for seeking to cut a bloated Defense Department and for not being bellicose enough in the Middle East, two assertions with which I cannot agree.
Defense and war spending has grown 137% since 2001. That kind of growth is not sustainable.
Adm. Michael Mullen stated earlier this year that the biggest threat to our national security is our debt.
If debt is our gravest threat, adding to the debt by expanding military spending further threatens our national security.
While I would always stand up for America and preserve our ability to defend ourselves, a less aggressive foreign policy along with an audit of the Pentagon could save tens of billions of dollars each year without sacrificing our defense. To dismiss either idea is to miss the very compromise that will enable us to balance our budget. That compromise would be for conservatives to admit that not every dollar spent on the military is sacred or well-spent and for liberals to admit that not every dollar spent on domestic entitlements and welfare is necessary.
In North Africa and the Middle East, our problem has not been a lack of intervention. In the past 10 years we have fought two full wars there, and bombed or sent troops into several others.
This past year, President Obama illegally began a war with Libya, taking sides with the rebels to unseat an admittedly bad man in Moammar Gadhafi. There were several problems with this policy: First, the president did not seek or get the necessary constitutional authority from Congress for this military action. If our Constitution is to mean anything it must be applied even in times of war, when those seeking to exercise power do not find it expedient.
Just as importantly, the Libyan rebels were assisted with virtually no one in the administration or in Congress demanding to know who these people were that we were arming and propping up. No one seemed to understand that in toppling Libya's dictatorship, we were leaving in its wake an unformed, unorganized government without a centralized structure, one that would have a difficult time keeping order among the more than 100 tribes that make up Libya.
This "act first, think later" foreign policy has real consequences. We've seen our embassies and consulates stormed in more than one country. Our diplomats and security team were killed. Our flag is being burned, our country mocked.
The proper response to this would be to step back and think of whether we really need to be involved in these countries in the way we have been. Instead, both parties rush headlong into more places they don't understand, exemplified Monday by Romney urging action to arm Syrian rebels and topple President Bashar al-Assad.
But just who are these rebels? What will they do when in power? Is this really in our vital national interest?
We've been 10 years in Afghanistan and we can't identify friend from foe. Do you think we can, with certainty, identify friend and foe in Syria?
Before taking our country closer to war, shouldn't we at least ask the viewpoint of the significant Christian population in Syria? News reports indicate they are wary of the rebels and are either sitting the fight out or siding with al-Assad. Al-Assad is by no means a saint but Christians flocked to Syria from a war-torn Iraq because they feared al-Assad less than the Islamic government we brought into being.
Before getting deeply involved, should someone ask: Are these rebels going to be implementing the death penalty for criticism of Islam?
There is ample evidence the rebels are being funded and armed by the most extreme Islamist elements and governments in the region. Is that where we want our funds and weapons to end up? We need to stop and think before we act.
I am not an isolationist or a pacifist. I heartily reject both labels. I believe in engagement in the world, with trade, commerce, diplomacy and a foreign policy that projects the greatness of America and her people. I would not hesitate to vote to send American troops to war to protect our country and our vital national security interests.
But we are in too many places, too often, and we don't seem to even know the reason -- or where we will end up when we're done. This foreign policy has created more enemies than it has vanquished. It has siphoned trillions of America's dollars. It has cost tens of thousands of casualties in the loss of the lives and limbs of our soldiers.
We owe it to ourselves, our soldiers and our children to take a more careful look at our foreign policy, to not rush into war, and to not attempt to score political points with wrongheaded policy ideas.
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The opinions expressed in this commentary are solely those of Rand Paul.