Sen. Rand Paul (R-Ky.), who has talked up his past border security bills in recent days, is introducing one to suspend the issuance of visas to refugees from Syria and up to 30 other countries, pending strict background checks.

"It's about time, and Paris should wake us up that we can't just let anyone come to this country," Paul said in a conference call with reporters. "Forty percent of immigration issues in our country are from visa overstays, and for those visiting us from countries that have large jihadist movements, this will be a bone of contention."

The full requirements in Paul's bill, as provided to reporters, also included a 30-day waiting period on "all entries to the U.S. in order for background checks to be completed, unless the traveler has been approved through the Global Entry program." That, said Paul, would include even citizens of France who wanted to study in the United States. Meanwhile, anyone seeking refugee status would only be eligible for a visa if three steps were met.

1) Aliens already admitted from high-risk countries have been fingerprinted and screened, pose no terrorist risk, and are being monitored for terrorist activity
2) Enhanced security measures are in place to screen future applicants and prevent terrorists from entering the country
3) DHS' visa entry-exit system is 100 percent complete and a tracking system is in place to catch attempted overstays
Sen. Rand Paul (R-Ky.) alludes to the Boston Marathon bombings, saying refugees have attacked us before.

Paul's position put him in sync with a growing number of governors who want refugees stopped at the border, and arguably associated him with a harder line than Sen. Ted Cruz (R-Tex.). Since the Paris attacks, Cruz has suggested that Christian refugees might be handled differently than Muslims.

"I've supported private charitable causes to try to help Christians in Syria," said Paul. "Ultimately, there can be a place, but in the context of the security of our nation." In his view, the burden of accepting refugees needed to fall on "those who made the situation worse," i.e. Iran and the nations of the Middle East.

Since the Paris attacks, Paul has talked more forcefully about limiting refugees; he has criticized Sen. Marco Rubio (R-Fla.), a rival for the Republican presidential nomination, for opposing his Trust But Verify visa security amendment to the 2013 immigration bill.

At the same time, Paul is distancing himself from Rubio and other Republican hawks who have argued for further American involvement in Iraq and Syria to fight the Islamic State. Rubio and Gov. John Kasich (R-Ohio) have called for France to invoke Article 5 of the NATO treaty and bring the United States definitively into a war on the Islamic State.

"This is clearly an act of war and an attack on one of our NATO allies," Rubio said on ABC News's "This Week" on Sunday. "We should invoke Article 5 of the NATO agreement, and bring everyone together to put together a coalition to confront this challenge."

Paul was more cautious, noting that Article 5 could only compel countries to declare war in line with their own laws. "We could do it in the context of obeying our Constitution," Paul said. "Even if Article 5 were invoked, we've said we need a vote of Congress."

Asked if he would oppose any expanded action against the Islamic State — such as ground troops — without a new congressional vote, Paul repeated that "the constitution's pretty clear" on war powers.

"We'd need a new authorization," he said. "I also believe that there's ever to be a long-lasting victory that civilized Islam is going to have to stand up. In order for there to be a long-lasting victory, radical Islam will not be stamped out by Americans, or Christians, or the French for that matter... any force that occupies that area has to be a Muslim force."

Update: After rolling out the policy, Paul released a fundraising letter restating its term. The letter is below.

The first priority of the Commander in Chief is to make our country safe.  It is my top priority and I will continue to fight to make sure that as Ronald Reagan said, we have “peace through strength”.
The biggest national security risk facing our country today is being perpetrated by both Republicans and Democrats in Washington who have been cutting deals to make our borders less secure and allow the bad guys access to our country.
The terrorists in Paris utilized the refugee crisis as a means to penetrate European borders and ultimately commit acts of terror.  One of the lessons we should learn from the tragedy is that we have to be very careful and very cautious, extraordinarily cautious, about our immigration policies.
I have always felt that liberal immigration policies and insecure borders put our country at very serious security risk.   That is why I previously put forth the “Trust but Verify” amendment to Senator Rubio’s “Gang of 8” immigration bill. The policy I proposed would have increased the scrutiny of people coming into the country -- it is the type of legislation that we need to protect this country from people who seek to do us harm on our soil.
Unfortunately, Senator Rubio teamed up with liberal Senator Chuck Schumer to block all conservative amendments because they cut a deal on amnesty.  It was a huge mistake - not only for the bill - but also for our national security.  Simply put, Senator Rubio’s actions on amnesty should disqualify him from earning the support of conservatives within our party.  
How can we trust him to stand for conservative principles if he sells out on amnesty to liberals in Congress?
How can we trust him on national security if he recently pushed for the refugees who caused the Paris tragedy to come to America?
The answer is we can’t trust Marco Rubio to stand up for conservative principles and we can’t trust him on immigration.  The problem is, interventionists like Rubio have never met a war they didn’t want our sons and daughters to fight.  He wants our children to fight on the frontlines in the Middle East, but is unwilling to do what it takes to protect our country here at home from bad people who want to use liberal immigration policies to penetrate our borders.
You and I both know, we can’t fix the refugee crisis by blocking all conservative amendments and throwing money into foreign countries. Rubio has it all wrong and we know exactly what it will get us; dangerous wars, more debt, porous borders, and less safety here at home.
I will continue to stand for policies that make us more safe and oppose insider deals that sell out conservative principles.
In liberty,
Rand Paul