When Congress returns to Washington in September, the political establishment will be sharply focused on the looming battle over the federal budget. In all likelihood, no consensus will be found and a continuing resolution will be required to continue funding the government.

As part of this year’s budget battle, some conservatives are drawing a line in the sand and suggesting that the government may not be funded at all unless the president’s signature first-term policy accomplishment, the Affordable Care Act (a.k.a. ObamaCare), is defunded. While this outcome is unlikely, the fight over this issue among Republicans is sure to be fierce.

But a potentially greater battle is brewing over proposals to address the sexual assault crisis within the military. The battle lines have been drawn by proponents of the leading reform proposals, and much like their own political campaigns, outside groups are stepping forward to throw the punches while the politicians stick to civil but vigorous public debate.

With the estimated number of incidents of unwanted sexual contact within the military climbing back up to over 26,000 last year, lawmakers and advocates have grown impatient with senior defense leaders. After 25 years of promises of reform, commitments to crack down, and continuous refrains of “zero tolerance,” the problem appears to be continuing unabated at best, and possibly worsening.

High profile incidents involving the very personnel charged with preventing sexual assault in some branches and on some installations allegedly committing sexual assaults themselves have incensed lawmakers, advocates, and the public and underscored the Pentagon’s inability to get the crisis under control. Now, Congress is stepping in to mandate more fundamental reforms, and there is decreasing patience and tolerance for the Pentagon’s pleas for the more aggressive reform factions within Congress to slow their roll.

Everyone in Congress seems to agree that the status quo of the military’s sexual assault policy is not cutting it anymore, but that is where widespread agreement ends. Where to go next and how to go about reforming the way the military deals with and prosecutes sexual assault cases is where the real battle begins.

Senator Kirsten Gillibrand (D-NY) crafted and introduced a bold proposal, the Military Justice Improvement Act (MJIA), that would take all crimes for which the punishment could be more than one year in confinement and that are not specifically military in nature, and  transfer the disposition authority for those crimes (i.e., the decision of whether to send the case to trial) to a cadre of professional military prosecutors. This would effectively remove from both the victim’s and the alleged perpetrator’s chain of command the ability and responsibility to decide whether a reported case of sexual assault - or any other serious crime - is prosecuted.

Senator Gillibrand, whose proposal is supported by a coalition of victim advocacy groups as well as a few veterans organizations (full disclosure: IAVA, the organization for which I work, is a proponent of the MJIA), asserts that her proposal solves one of the main problems that many victims say keep them from reporting sexual assaults committed against them - their fear that the chain of command responsible for deciding whether to prosecute the case will find a way to rationalize not moving the case forward. In other words, they are reluctant to report and experience potential blowback (harassment, retaliation, ostracization, career obstruction, etc.) if nothing may be done in the end anyway.

Senator Gillibrand’s legislation is opposed by senior defense leaders, who would prefer to see that disposition authority stay within the chain of command. Instead, the Pentagon is supporting an alternative legislative proposal sponsored by Senate Armed Services Committee Chairman Carl Levin (D-MI) that would keep this decision point within the chain of command but add automatic higher level review, up to and including the secretary of the service concerned, in cases where a Staff Judge Advocate recommends prosecution of a sexual assault case but the commander refuses to send the case to court-marital.

This proposal is also championed by Senator Claire McCaskill (D-MO), a former civilian prosecutor. Senator McCaskill is known for being tough on the Defense Department for its failures to adequately address the sexual assault epidemic, and she is the only member of the Senate to have actually prosecuted sexual assault cases herself. She believes, however, that taking disposition authority out of the chain of command would actually result in fewer prosecutions of sexual assault and, therefore, continue to reinforce victims’ perception that perpetrators are not being brought to justice.

In recent testimony before the Senate Armed Services Committee, Admiral James Winnefeld, Vice Chairman of the Joint Chiefs of Staff, revealed that under the current chain of command-dominated system, the Army had prosecuted 49 cases of sexual assault within the last two years that civilian prosecutors had declined to prosecute. Marine Corps commanders had referred another 28 cases to court-martial that civilian prosecutors passed on trying.

This, supporters of Senator Levin’s proposal argue, demonstrates why keeping disposition authority within the chain of command is important. Professional prosecutors, including military prosecutors, make decisions about whether to send a case to trial or court-martial based on factors such as the weighing of evidence, the likelihood of conviction, and the interests of the government. Commanders, however, may opt to send a “he said, she said” case to trial to let a judge or jury explore and decide the facts more thoroughly, or just to send a message throughout his or her unit that the military is serious about combatting sexual assault.

Supporters of Senator Gillibrand’s proposal still maintain that higher-level review of cases in which commanders decline to prosecute is not enough to restore victims’ faith and trust in the system and encourage them to come forward and report these types of crimes in greater numbers. They also fear that the intense focus on sexual assault from above could result in perpetrators going free because of undue command influence, an unfortunate dilemma that has already started to appear as an issue in some ongoing cases. This uniquely military objection to a conviction or sentence might have been avoided in these cases by having an independent military prosecutor decide whether to send them to trial.

With the stakes so high and the issue politically ripe this year, the battle over the best structural reform solution is heating up. Just before the August recess, Senator Gillibrand announced that she now has seven Republicans on board with supporting her proposal. She has even managed to win over the likes of Tea Party conservatives like Senators Rand Paul (R-KY) and Ted Cruz (R-TX), in addition to more traditional conservative Republicans such as David Vitter (R-LA) and Chuck Grassley (R-IA).

This sets up a unique showdown for the Senate going into the post-recess period. By November, the massive defense spending and policy bill through which one of these proposals will likely pass is expected to move on the floor of both chambers.

However, unlike most other battles that break along party lines, or the upcoming battle over whether to shut down the government if ObamaCare is defunded, which is set to split only the Republican caucus, the battle over how to restore trust in the military justice system among sexual assault survivors and their advocates and ensure that perpetrators are adequately and fairly prosecuted is set to split both parties and forge new bipartisan alliances behind competing proposals.

Fortunately for reform advocates, change in some form is virtually guaranteed and the status quo is all but dead. But the true measure of success will be the objective numbers reported the following year. Will there continue to be such a huge divide between the estimated incidents of unwanted sexual contact and victim reports of those incidents? Or will future battles over more fundamental reforms be necessary to finally get this problem under control?