With 2013 approaching termination, it may be a good time to review the five most portentous events and developments of the year. These are events and developments that hold out high prospects for ongoing impact, will likely generate derivative events and developments, and will spawn indirect as well as direct consequences. This is a subjective exercise, with plenty of room for alternative perspectives and debate. But somebody has to begin the discussion, so here are my five most portentous events and developments of 2013.

The Decline of the Obama Presidency: A big contributor to this development, of course, has been the disastrous rollout of the president’s Affordable Care Act, which has sapped Obama’s political standing precipitously and placed his party on the defensive for the coming campaign year. But the administration’s decline is a product not merely of the Obamacare fiasco. The president’s inability to sustain a serious agenda thus far in his second term has rendered him hapless in the eyes of many Americans. In domestic policy, nothing of consequence is happening under the president’s leadership. True, he has a cantankerous House of Representatives eating at him constantly. But that is no excuse. Many successful presidents have had to contend with obstructionist forces in Congress and still managed to bring about significant accomplishments. Ronald Reagan and Bill Clinton come to mind. Obama has squandered any opportunity he may have had to sway Congress toward a positive presidential agenda, either through force of argument, going directly to the people, or exercising political cajolery mixed with traditional horse-trading and the subtle political threat. The result over the next three years is likely to be inertia, increasingly feisty political squabbling, and ever-growing voter angst.

In foreign policy, the president has demonstrated that he doesn’t really have one. His zig-zag effort to deal with Syria, his inability to direct his policy focus away from the Middle East and toward the Far East, his reactive approach to Russia and China, his fluctuation between expressions of Wilsonian idealism and cautious realism—all these reflect a foreign policy that lacks strategic coherence, vision and consistency.

I have written previously in these spaces that only three presidents have been reelected by a smaller margin that Obama’s, and all faltered in their second terms, followed by the opposition party taking the White House at the next election. The three are Grover Cleveland, Woodrow Wilson and George W. Bush. If Obama wishes to avoid their fate, he must demonstrate a level of leadership that has thus far eluded him. If he can’t do it, the decline of his presidency will become progressive, and the country will continue to suffer.

China’s Declaration of a Broad "Air Defense Identification Zone" in the East China Sea: This caused a significant flare-up in November when the United States first protested the move as a "destabilizing attempt to alter the status quo in the region," then sent two B-52 bombers into the claimed airspace as a show of resolve in the matter. Other Asian nations also entered the airspace as a demonstration of solidarity with the American position.

But the Chinese move, which was accompanied by expressions of resolve to take "defensive emergency measures" against noncommercial aircraft entering the zone, was a significant provocation by any measure. It signified that the current Chinese government is coming increasingly under the sway of China’s nationalist factions, which want to project Chinese power more broadly in the region and force the United States into a less predominant role there than it has enjoyed since World War II. Said Defense Ministry spokesman Geng Yansheng, "China has the ability to take effective management and control of the relevant airspace."

China did not seek to enforce its declaration when other countries ignored it, and thus the tensions unleashed by the China move began to wane as the holiday season approached.

But this is a serious matter that puts China on a course of increased aggressiveness in the region and figures to stir greater tensions with its neighbors and with the United States. As Patrick Cronin of the Center for a New American Security put it in an interview with the Washington Post: "The Chinese aren’t going to back off. We’re not going to back off. So right now, the trajectory is that there’s going to be some kind of mishap in the next couple of years."

Perhaps some kind of mishap can be avoided. But this is indeed a portentous development that is likely to escalate in the near term.

The Assault on the Senate Filibuster: It would be difficult to overstate the long-term consequence of Senate majority leader Harry Reid’s blow against the ancient institutional tradition of the filibuster, which has ensured that Senate deliberations were more than just the majority walking over the minority. That was the role of the Senate—to serve as an institutional bulwark against governmental encroachment and to ensure that actions taken by our increasingly powerful and intrusive federal government must get serious and extended deliberation before they can become law. That also contributed for decades to the Senate’s cultural ethos that collegiality and cooperation must transcend ideology or partisan fervor.

Reid’s action, changing a Senate rule with a mere Senate majority vote, ostensibly eliminated the filibuster only for the confirmation of judges and executive nominees (though not for Supreme Court nominees). But eventually the traditional filibuster won’t survive this unprecedented (since 1806) assault. And certainly it won’t survive the new precedent that Senate rules can be changed by a mere majority vote. Ultimately, as old traditions give way to this promiscuity of action, it will become apparent that the Senate has no rules worthy of the name. With the majority vote precedent, the rules will be changed willy-nilly, at will. Partisanship will reign, as it does in the House.

Eventually it won’t be just the Senate that will change profoundly. So will American democracy. The portents are hovering over the United States in profusion.

The Snowden Breach: Edward Snowden, the former contractor for the U.S. National Security Agency, unleashed a series of powerful developments, both at home and abroad, when he stole vast stores of highly classified and super-sensitive information from the NSA and began making them public. Government officials say they have no way of knowing precisely how many super-secret documents Snowden actually stole before he set off on his global trek to find a country willing to grant him permanent political asylum (currently he is living temporarily in Russia). But the magnitude is immense, and so is the impact. At home, Snowden has single-handedly transformed the national debate about NSA spying and information collection. This debate will continue for years, with the newly exposed NSA on the defensive as never before. A federal judge has ruled that just about the entire NSA collection of telephone metadata is unconstitutional, further fueling the controversy. It’s an open question whether that ruling will prevail on appeal, but in the meantime the agency operates under a political cloud. It is unlikely to survive in precisely its current form. So also has the Foreign Intelligence Surveillance Court, which oversees NSA activity, come under increased scrutiny and faces a likely overhaul.

Meanwhile, officials in foreign capitals are bristling at revelations of NSA spying on governmental leaders abroad and its probes of the internal workings of many governments around the world. These tensions will almost certainly increase as more revelations tumble out.

Whatever one thinks of Snowden’s actions (and those who view him as a traitor have a very strong case), it can’t be disputed that he has severely transformed the political landscape in America when it comes to electronic surveillance. For good or ill, the NSA, and the issues and controversies surrounding it, will never be the same.

Obama’s Diplomatic Opening to Iran: It doesn’t negate the earlier item about Obama’s declining presidency to say that his effort to open up a dialogue with Iran over its nuclear program constitutes a highly significant presidential initiative. It can’t be denied that prospects are probably modest that this overture will actually yield serious diplomatic results. But, after nearly three and a half decades of tension between the two countries, there is at least a chance that U.S.-Iranian relations might become somewhat normalized. Perhaps the time is just right for such a development; perhaps not. But, in diplomatic terms, Obama’s initiative, and the interim agreement that it produced, probably ensure that the two countries will deal with each other a bit more openly and with greater prospects for mutual understanding.

Of course, there are powerful elements in both countries that strenuously oppose any rapprochement, and they could in the end destroy prospects for any kind of normalization and for an Iranian move toward a more diplomatic approach to international relations. But that adds significance to Obama’s initiative because, in pursuing it, he has invited heated opposition from the country’s powerful Israel lobby, particularly the American Israel Public Affairs Committee, or AIPAC. For years there has been an assumption in Washington that politicians, even presidents, can’t buck this lobby without paying a heavy price. But Obama’s initiative is supported in the polls by wide margins, nearly two to one in some surveys. And the opposition to the initiative stirred one influential journalist, Thomas Friedman of the New York Times, to produce a withering column on the subject. "Never," he wrote, "have I seen more lawmakers—Democrats and Republicans—more willing to take Israel’s side against their own president’s. I’m certain this comes less from any careful consideration of the facts and more from a growing tendency by many American lawmakers to do whatever the Israel lobby asks them to do in order to garner Jewish votes and campaign donations."