When Donald Trump ran for President, he promised a "better deal" to constrain Iran's nuclear program and pledged to pressure Tehran into curbing its aggressive behavior across the Middle East. Like so many of President Trump's promises, these proved to be just empty words. Instead, he recklessly tossed away a policy that was working to keep America safe and replaced it with one that has worsened the threat. This past month has proven that Trump's Iran policy is a dangerous failure. At the United Nations, Trump could not rally a single one of America's closest allies to extend the UN arms embargo on Iran. Next, Trump tried to unilaterally reimpose UN sanctions on Iran, only to have virtually all the UN security council members unite to reject his gambit. Now there are reports that Iran has stockpiled 10 times as much enriched uranium as it had when President Barack Obama and I left office. We urgently need to change course. I have no illusions about the challenges the regime in Iran poses to America's security interests, to our friends and partners and to its own people. But there is a smart way to be tough on Iran, and there is Trump's way. He ignored our closest allies and walked away -- alone, without a plan -- from a deal that put the world's eyes and ears inside Iran's nuclear program and was verifiably blocking Iran's pathways to a nuclear weapon. He has repeatedly ratcheted up tensions, risking bringing us closer to another Middle Eastern war without a realistic strategy or endgame. He has lurched into risky escalations that endangered our troops -- and then downplayed their brain injuries as "headaches." By any objective measure, Trump's "maximum pressure" has been a boon to the regime in Iran and a bust for America's interests. Five years ago, American-led diplomacy produced a deal that ensured it would take Iran at least a year to produce enough fissile material for one bomb. Now -- because Trump let Iran off the hook from its obligations under the nuclear deal -- Tehran's "breakout time" is down to just a few months. And there is no serious diplomacy underway to reverse it. The bottom line is that Iran is closer to a nuclear bomb today than it was when Donald Trump took office. And Trump has no answer for that. Five years ago, even Russia and China stood with our European allies behind an American-led approach to Iran's nuclear program. Now, America stands alone. Trump's policies have pushed Russia and China closer to Iran, while reducing transatlantic relations to their lowest point in decades. When tensions spiked early this year, instead of rallying to America's side, our European allies called for "all parties to exercise utmost restraint and responsibility." Because Trump violated an agreement that America itself negotiated and then acted recklessly, other world powers now devote their energies to opposing US policy instead of working alongside us to counter Tehran. This mix of confrontation and isolation will leave us with the worst of both worlds: no arms embargo or snapback of UN sanctions, but also no deal to constrain Iran's nuclear program -- and no plan except to recklessly double down. Five years ago, Iran was a bad regional actor requiring active deterrence and pushback. But it had not conducted a major attack on US forces in the region in years. Since Trump took office, Iran or its proxies have killed two American service members and a US contractor, severely injured more than 100 US troops, damaged Saudi oil facilities and disabled commercial ships transiting the Gulf. Before Trump, years went by without a militia rocket attack on US facilities in Iraq. Now they happen regularly. Instead of restoring deterrence, Trump has emboldened Iran. Instead of ending "endless wars," Trump has repeatedly brought America to the brink of a new one. If this is what Trump considers success, I would hate to see what failure looks like. The good news is that there remains a better way. Here's what I would do as President. First, I will make an unshakable commitment to prevent Iran from acquiring a nuclear weapon. Second, I will offer Tehran a credible path back to diplomacy. If Iran returns to strict compliance with the nuclear deal, the United States would rejoin the agreement as a starting point for follow-on negotiations. W ith our allies, we will work to strengthen and extend the nuclear deal's provisions, while also addressing other issues of concern. This includes working aggressively to free unjustly detained Americans and calling out the regime for its ongoing violations of human rights, including the execution of wrestler Navid Afkari this week and the wrongful detention of political prisoners, such as human rights lawyer Nasrin Sotoudeh. And we will work to help our partners reduce tensions and help end regional conflicts, including the disastrous war in Yemen. I will also take steps to make sure US sanctions do not hinder Iran's fight against Covid-19. And on day one, I will repeal Trump's disgraceful travel ban targeting a number of Muslim-majority countries, among others. Third, we will continue to push back against Iran's destabilizing activities, which threaten our friends and partners in the region. Drawing on the record-setting US-Israel security assistance agreement signed when I was Vice President, America will also work closely with Israel to ensure it can defend itself against Iran and its proxies. We will continue to use targeted sanctions against Iran's human rights abuses, its support for terrorism and ballistic missile program. If Iran chooses confrontation, I am prepared to defend our vital interests and our troops. But, I am ready to walk the path of diplomacy if Iran takes steps to show it is ready too. With the world back at America's side, a Biden administration will make it a priority to set Iran policy right. [Former Vice President Joe Biden is the Democratic nominee for President. The views expressed in this commentary are his own.]