The Senate will take up the massive Pentagon policy bill this week, providing a stage for high-profile debate on simmering national security issues ranging from transgender troops to the growing North Korea nuclear threat.

Senators have already filed hundreds of amendments to the defense bill, among them language to allow transgender people to serve openly in the military, establish a North Korea strategy, limit arms sales to U.S. allies, define U.S. objectives in Afghanistan and block the creation of a new military service.

The debate will also put, front and center, Senate Armed Services Chairman John McCain‘s sharp disagreements with President Donald Trump on Russia and a number of other national security issues, adding a layer of new drama to the upper chamber’s consideration of the defense bill.

Transgender Issues

In a direct challenge to Trump’s recent directive to ban transgender service members, New York Sen. Kirsten Gillibrand, the top Democrat on the Armed Services Personnel Subcommittee, is offering two amendments that would protect their jobs and benefits.

The amendments would give Congress 60 days to review a forthcoming report from the Defense secretary on the impact of transgender men and women in the military before the administration can take any action against them.

In the meantime, transgender military members could not be penalized for their gender identity. The amendment is likely to gain bipartisan support, including potentially from McCain.

“It would be a step in the wrong direction to force currently serving transgender individuals to leave the military solely on the basis of their gender identity,” McCain said in a statement shortly after Trump issued his directive in August. “The Pentagon’s ongoing study on this issue should be completed before any decisions are made with regard to accession.”

Space

An amendment from a bipartisan pair of senators will seek to kill a House effort to start up a new service branch.

Florida Democrat Bill Nelson and Arkansas Republican Tom Cotton are offering an amendment that would prohibit authorized funds from being used for Space Corps, a new military service created in the House’s version of the defense bill.

The House proposal, which had the full backing of House Armed Services Chairman Mac Thornberry of Texas and Adam Smith of Washington, the panel’s top Democrat, could end up as a key negotiating point when the House and Senate meet in conference later this year.

Republican Sen. Cory Gardner and Democratic Sen. Michael Bennet, who both represent Colorado, have drafted an amendment seeking a sense of Congress to define space as a “warfighting domain.”

The amendment also calls on Congress to recognize the National Space Defense Center, a joint military and intelligence venture located in Colorado, as “critical” to defending U.S. space assets.

North Korea

A host of amendments filed by Democrats will seek to more tightly define the Pentagon’s posture vis-à-vis North Korea.

Indiana Democrat Joe Donnelly filed an amendment demanding from the White House a strategy to confront North Korea and its expanding nuclear weapons program no later than 90 days after passage of the bill. The amendment also requires quarterly unclassified updates from the White House on the administration’s progress.

Hawaii Democrat Mazie K. Hirono offered an amendment designed to boost U.S. deterrence capabilities in the Asia-Pacific region to counter an emboldened North Korea.

Her proposal calls for Congress to recognize North Korea’s first successful test of an intercontinental ballistic missile and for the Defense secretary to submit to Congress a plan to “enhance” deterrent capabilities in the Asia-Pacific region within 30 days of the measure’s passage.

The lengthy amendment calls for more military exercises with regional allies, a more robust military presence in the region, including the increased presence of missile defense, long-range and intermediate strike assets. The measure also calls on increased military sales to regional allies and “necessary modifications” to the U.S. nuclear presence in the Asia Pacific, including the possible re-deployment of nuclear-armed submarines.

As Hirono seeks a more robust military presence in the region, her fellow Democrat, Edward J. Markey of Massachusetts, is looking to restrain the military’s reach.

Markey’s amendments seek to prohibit authorized funds from going toward the Pentagon’s long-range standoff weapons program and the W80 warhead. In a separate amendment, Markey calls for a prohibition on the first-use of nuclear weapons unless authorized by Congress.

Ongoing Conflicts

Senators are also using the annual policy bill to check long-running conflicts in South Asia and the Middle East.

McCain filed an amendment seeking a sense of Congress on the Afghanistan and South Asia strategy. The amendment calls for an increase in U.S. counter-terror forces in Afghanistan.

Farther West in the region, lawmakers are looking to draw down U.S. involvement in military conflict. Massachusetts Democrat Elizabeth Warren has an amendment requiring a study of air-to-ground munitions supplied by the U.S. to ally Saudi Arabia no more than 90 days after passage of the bill.

An amendment from Oregon Democrat Jeff Merkley takes Warren’s proposal one step further by proposing a complete ban on authorized funds being used in the transfer of cluster munitions — the bombs typically dropped from Saudi jets in the Yemen conflict — to the Saudis.

Both Warren and Merkley are looking to remove the U.S. hand from the Yemeni Civil War, a protracted conflict pitting Saudi and Iranian-backed proxy forces against each other. Saudi Arabian forces have frequently performed air-to-ground bombings in Yemen in support of their preferred Sunni proxies.

Observers of the conflict have reported numerous civilian casualties as a result of the bombing runs. Warren’s amendment would demand from the Defense secretary and Director of National Intelligence a report on those civilian casualties in Yemen in order to determine if U.S. munitions were used in the bombings.

Russia

Democrats Amy Klobuchar of Minnesota, Richard J. Durbin of Illinois, Sheldon Whitehouse of Rhode Island and Warren will seek to limit U.S.-Russian cooperation on cybersecurity issues through an amendment that would bar funds from being used for any joint cyerbersecurity initiatives by the two countries.

Trump and Russian President Vladimir Putin announced their intentions to work together on a cybersecurity initiative in July at the G-20 summit in June. The Democrats’ amendment is likely to gain bipartisan support as a number of Senate Republicans have acknowledged concerns about Russian cyber interference in the 2016 U.S. presidential election.

BRAC

McCain and Senate Armed Services ranking member Jack Reed, D-R.I., have filed an amendment that takes a novel approach to closing bases by dispensing with the usual independent Base Closure and Realignment Commission, or BRAC, and requiring Congress to vet an administration plan to revise U.S. military infrastructure.

Begun in 1988, the BRAC process was created precisely because lawmakers found it difficult to rise above parochial politics and close bases. Still today, many lawmakers, particularly those with military assets in their states and districts, fiercely oppose closing bases.

But the politics of the issue may have shifted just enough to make it more likely than not that a new round of base closures is in the offing, experts say.

Sage Grouse

Noticeably absent in the defense authorization bill in the House, the sage grouse will again enter congressional debate. Utah Republican Mike Lee filed an amendment that seeks greater protections for the bird native to the Western United States by facilitating state management plans that work to protect sage grouse habitats.

John M. Donnelly contributed to this report.