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SPRINGFIELD, Virginia - In this battleground state where defense is an essential part of the economy, Paul Ryan brought up the looming issue of $500 billion in defense cuts, also known as sequestration, for the first time since he joined Mitt Romney's ticket. He accused the president of being behind the "devastating cuts."

"Now there's one thing we're going to have to deal with to make sure we protect jobs in Virginia and around America," Ryan said. "And that is these devastating defense cuts that president Obama is promising. That is the lack of leadership that he is providing. They call it sequester and all of that. Well, I tell you what. In the House, we already passed the bill to cut spending in other areas of government to make sure that these devastating cuts to defense never occur so we don't put Virginians out of work and so we have a strong national defense. That's extremely important."

The cuts are part of a political battle that started last summer. They are mandated by the Budget Control Act, which was signed into law last August by President Obama in exchange for a $2.4 trillion increase in the debt limit.

House Speaker John Boehner had insisted that any increase in the debt limit be matched dollar-for-dollar in spending cuts and reforms, but as the federal government ran critically low on cash, Congress had only agreed to about $1.2 trillion in savings. Still, the debt limit was increased under an agreement which called on a "Supercommittee" to negotiate an additional $1.2 trillion in savings, or face sequestration (i.e., automatic cuts).

After the committee failed to strike a deal, the country was left with sequestration. The Obama administration, including Defense Secretary Leon Panetta, have warned what the cuts would mean for the military, but Romney has also hit the president over the cuts on the campaign trail.

The cuts would mean about $500 billion to defense and about $500 billion to entitlements or social programs. Ryan said the budget slashing could also affect the country's national security, which he called the "first responsibility of our federal government."

"And one of the critical means and needs for a strong national defense is because the world needs America's leadership," Ryan said. "In the past day, Iran's president called our ally Israel, quote, a cancerous tumor that must be excised. Let me be really clear. Under President Romney, our adversaries will think twice about challenging America and our allies because we believe in peace through strength. There will be no daylight between America and our friends around the world. Strong national defense, peace through strength, strong relationship with our allies."

In state-organized protests Friday, Iranian president Mahmoud Ahmadinejad did call Israel a "cancerous tumor."

"You want a new Middle East? We do too, but in the new Middle East … there will be no trace of the American presence and the Zionists," Ahmadinejad said at Tehran University.

Earlier Friday, Romney put out a statement calling the comments "outrageous" and saying America has to "lead the world" in stopping Iran from "obtaining nuclear weapons capability."

After not mentioning it on the stump at his earlier event in Glen Allen, Virginia Friday, Ryan brought back the issue of Medicare - one that will undoubtedly trail him throughout the campaign - accusing the president of treating the program "like a piggy bank."

"We want this debate on Medicare," Ryan told the cheering crowd of hundreds in a high school gym. "We want this debate, we need this debate and we are going to win this debate. I'll tell you why. There's only one on Medicare, only one person who treated Medicare like a piggy bank, and that's President Obama, who took $716 billion from that program to create Obamacare, and that affects current seniors, and his campaign calls this an achievement.

"Do you think raiding Medicare to pay for Obamacare is an achievement?" he asked. "Why don't we just get rid of Obamacare altogether?"

Ryan actually endorsed the same cuts in his signature budget plan, the same plan Romney has said he would sign if he became president. Ryan says he was forced to build his plan on those cuts because they were signed into law and he had to base his plan off of what was already current law.

The $716 billion in cuts do not affect benefits for today's seniors. Instead, they reduce provider reimbursements and curb waste, fraud and abuse. Ryan's own plan has come under attack by Democrats because it would fundamentally change the plan making it a voucher program that could cost senior citizens more. Ryan says his plan is the only way to save Medicare from going completely bankrupt.

It's a complex discussion, something the new vice presidential candidate will focus on Saturday when he travels to the world's largest retirement community, The Villages, in central Florida. He will be accompanied by his 78-year-old mother, Betty Douglas.