Such a policy is a mistake and would harm the U.S. military. It would jeopardize the readiness of the military in a time of increasing international instability, and demonstrate a remarkable willingness to undercut both institutions and key military leadership. The military’s reticence to implement such a policy is based on a clear understanding both of the facts and the long-term ramifications of such a reckless pronouncement.

From a human capital perspective, Trump’s invectives go against best practices of organizational management, ranging from undercutting senior leaders he would be better served by empowering, such as Secretary of Defense James Mattis and the Joint Chiefs of Staff, as well as conveying to those within the military that their organization may revoke promises and turn on them at any point in time. This is a far cry from the “no soldier, sailor, airmen, or marine left behind” mission that has consistently characterized U.S. military operations and ethos.

When it comes to the fiscal ramifications of service, a study commissioned by the Pentagon indicates there is little fact behind this claim, with estimates putting the cost of transgender service members at less than one-tenth of 1% of the military health care budget. This clear disregard for facts and precedent generates instability in the guarantees the country makes to the young Americans who choose to serve in uniform, and quite possibly influences those considering service to look elsewhere for opportunities.

In trying to attract high-quality personnel, the military already faces an uphill battle in an improving economy, with declining rates of eligibility and interest among today’s youths. This becomes a multifaceted problem for recruiting and retention in the wake of Trump’s surprise announcement. First, if the military discharges currently serving transgender personnel, it will unexpectedly lose already trained and serving members of the force, in a time when many services are trying to increase their end strength. The cost of recruiting and training new personnel to fill this gap would be orders of magnitude greater than any potential savings on their health care. In addition to this loss, the military would likely face litigation from those who are forced to leave. The recruiting pool would also shrink, with transgender individuals no longer eligible, despite being twice as likely to serve.

Furthermore, millennials are far more likely than their parents to feel strongly about equal rights for LGBT persons, and this maltreatment could ostensibly have repercussions amongst the non-transgender youths considering military service. Discriminatory practices based upon one’s identity may give pause to those on the cusp of considering service, as well as to the influencers who play a critical role in either encouraging or dissuading people from joining the military.

Prior to President Trump’s flurry of tweets, Secretary Mattis had ordered a six-month study on the integration of transgender personnel, and the removal of those already serving was believed to be largely off the table, and unsupported by the Joint Chiefs of Staff. Indeed, in the wake of the announcement, the Pentagon referred all questions back to the White House, as well as disseminating a memo that no changes were to be implemented until official guidance was received and all personnel should continue to be treated with respect. The implied rebuke of the president speaks to the unconventional and disturbing way the announcement was handled, lacking consideration for service members and military readiness writ large. The disregard for the Department of Defense undermines senior military leadership, while eroding military readiness in its own right.

The latest reports that the White House and Department of Defense are now discussing the issue, despite broad bipartisan pushback against such a sweeping measure, are a concerning development. If executed, this policy will be at the eventual expense of our nation’s military and those who do choose to serve.

Amy Schafer is a research associate for the Military, Veterans, & Society program at the Center for a New American Security.